Growth percentile meaning

Growth Charts (for Parents) - Nemours KidsHealth

What Are Growth Charts?

Kids grow at their own pace. Big, small, tall, short — there is a wide range of healthy shapes and sizes among children. Genetics, gender, nutrition, physical activity, health problems, environment, and hormones all play a role in a child's height and weight. And many of these things can vary widely from family to family.

So how do doctors figure out whether kids' height and weight measurements are "healthy"? Whether they're developing on track? Whether any medical problems are affecting growth?

Doctors use growth charts to help answer those questions. Here are some facts about growth charts and what they say about a child's health.

Why Do Doctors Use Growth Charts?

Growth charts are a standard part of your child's checkups. They show how kids are growing compared with other kids of the same age and gender. They also show the pattern of kids' height and weight gain over time, and whether they're growing proportionately.

Let's say a child was growing along the same pattern until he was 2 years old, then suddenly started growing much more slowly than other kids. That might mean there is a health problem. Doctors could see that by looking at a growth chart.

Does a Different Pattern Mean There's a Problem?

Not necessarily. Doctors consider the growth charts along with a child's overall well-being, environment, and genetic background. For example:

Is the child meeting other developmental milestones?
Are there other signs that a child is not healthy?
How tall or heavy are the child's parents and siblings? Was the child born prematurely?
Has the child started puberty earlier or later than average?

Are All Kids Measured on One Growth Chart?

No. Girls and boys are measured on different growth charts because they grow in different patterns and at different rates.

And one set of charts is used for babies, from birth to 36 months. Another set is used for kids and teens ages 2–20 years old. Also, special growth charts can be used for children with certain conditions, such as Down syndrome, or who were born early.

What Measurements Are Put on the Charts?

Until babies are 36 months old, doctors measure weight, length, and head circumference (distance around the largest part of the head).

With older kids, doctors measure weight, height, and body mass index (BMI). It's important to look at and compare weight and height measurements to get a full picture of a child's growth.

Why Is Head Circumference Measured?

In babies, head circumference can give clues about brain development. If a baby's head is bigger or smaller than most other kids' or the head stops growing or grows too quickly, it may mean there is a problem.

For example, an unusually large head may be a sign of hydrocephalus, a buildup of fluid inside the brain. A head that's smaller than average may be a sign that the brain is not developing properly or has stopped growing.

What Are Percentiles?

Percentiles are measurements that show where a child is compared with other kids. On the growth charts, the percentiles are shown as lines drawn in curved patterns.

When doctors plot a child's weight and height on the chart, they see which percentile line those measurements land on:

The higher the percentile number, the bigger a child is compared with other kids of the same age and gender, whether it's for height or weight.
The lower the percentile number, the smaller the child is.

For example, if a 4-year-old boy's weight is in the 10th percentile, that means that 10% of boys that age weigh less than he does and 90% of boys that age weigh more.

Being in a high or a low percentile doesn't necessarily mean that a child is healthier or has a growth or weight problem. Let's say that the 4-year-old boy who is in the 10th percentile for weight is also in the 10th percentile for height. So 10% of kids are shorter and weigh less than he does, and most kids — 90% — are taller and weigh more. That just shows that he's smaller than average, which usually doesn't mean there is a problem. If his parents and siblings are also smaller than average, and there are other signs that he's healthy and developing well, doctors would likely decide that there's no reason to worry.

What's the Ideal Percentile for My Child?

There is no one ideal number. Healthy children come in all shapes and sizes, and a baby who is in the 5th percentile can be just as healthy as a baby who is in the 95th percentile.

Ideally, each child will follow along the same growth pattern over time, growing in height and gaining weight at the same rate, with the height and weight in proportion to one another. This means that usually a child stays on a certain percentile line on the growth curve. So if our 4-year-old boy on the 10th percentile line has always been on that line, he is continuing to grow along his pattern, which is a good sign.

What Could Signal a Problem?

A few different growth chart patterns might signal a health problem, such as:

When a child's weight or height percentile changes from a pattern it's been following. For example: If height and weight have both been on the 60th percentile line until a child is 5 years old, and then the height drops to the 30th percentile at age 6, that might suggest a growth problem because the child is not following his or her usual growth pattern. But changing percentiles doesn't always mean there's a problem. Many kids may show changes in growth percentiles at some points in development, when it's normal for growth rates to vary more from child to child. This is particularly common during infancy and puberty.
When kids don't get taller at the same rate at which they're gaining weight. For example: If a boy's height is in the 40th percentile and his weight is in the 85th percentile, this means he's taller than 40% of kids his age, but weighs more than 85% of kids his age. That might be a problem. On the other hand, if he's in the 85th percentile for both height and weight and follows that pattern over time, that usually means that he's a healthy child who's just larger than average.

If you have any questions about your child's growth — or growth charts — talk with your doctor.

Percentiles and What They Mean

Written by Steven Jerome Parker, MD

Q: My baby is small but my pediatric provider says she is "following the curve" so he is not worried. What does that mean? I'm still worried!

A. If your baby is "following the curve" of the growth chart, she's paralleling one of the percentile lines on the chart, and the odds are good that her caloric intake is fine, no matter how much or how little milk she seems to be drinking.

On the other hand, if she is "falling off the curve," she's dipping below two or more percentile lines on the growth chart, and she may have inadequate nutritional intake. This could represent a real problem.

Growth Charts: How They Work

There are separate growth charts for weight, height, and head circumference.

These simply represent the average weight, height, or head circumference of a bunch of normal children. You will see the percentile lines on the chart running parallel to each other. The percentile lines include 5%, 10%, 25%, 50%, 75%, 90%, and 95%. (For more information, see the CDC's web site: www.cdc.gov/growthcharts/).

If a child's weight is at the 50th percentile line, that means that out of 100 normal children her age, 50 will be bigger than she is and 50 smaller. Similarly, if she is in the 75th percentile, that means that she is bigger than 75 children and smaller than only 25, compared with 100 children her age.

What Growth Charts Tell Us

The growth percentiles by themselves don't say much. What really matters is the rate of growth:

A normal rate of growth means the child's growth points closely follow a percentile line on the chart.
We usually don't worry about insufficient (or excessive) growth until a child's growth rate has crossed at least two percentile lines (e.g., from above the 90th percentile to below the 50th).
If a child's weight, height, or head size is below the 5th percentile, it's important to see if her growth points have always paralleled the 5th percentile line -- which would mean her growth rate is normal -- or if she is suddenly falling further behind, which is more concerning.

To see if your child is too skinny or overweight, there is a "weight for height" chart or a "BMI" index. These tell if your child's weight is close to what it should be, given her height.

How to Tell If Growth Could Be a Problem

One of the first signs that a child is not getting enough calories is when her weight increases at a much slower rate than her height and begins to fall below two percentile lines.

Depending on the extent of the poor caloric intake, the child's height could become "stunted," that is, the height begins descending on the growth chart.
If the lack of nutrition is severe and continues for an extended period of time, the head growth slows down, indicating that there are not enough calories for the brain to grow at a normal rate.

Similarly, a steady increase in weight, while the child's height increases at a much slower rate, indicates she may be putting too much extra meat on her bones. This can be a good thing or an early sign of a risk of obesity.

Tips:

Put the growth chart into context. No child's growth and development is always so smooth and perfect like the lines of the chart. Kids bounce up and down the growth charts, depending on appetite, feeding issues, illnesses, brief feeding strikes, etc.

Consider other signs of good health. Does your child appear otherwise happy and healthy? Is she making nice developmental progress? If the answers are yes, a problem is less likely.

When to Worry

If your child's growth rate slows down (weight, height, or head size) and she falls below two percentile lines, then you should explore the reason for the poor growth.

Dr. P's Pearl

Don't obsess about every up and down of your infant's growth chart. It's only potentially a problem when there is a persistent downward trend, usually lasting many months.

Percentile Calculator • Math • Online Unit Converters

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Random converter	Calculators Math Percentile calculator This calculator determines P th percentile for the original dataset. Example: calculate the 95th percentile for the following dataset: 3.77; 3.96; 4.26; 3.99; 3.79; 3.90; 4.30; 4.28; 4.16; 4.13; 4.03; 4.55; 4.56; 4.64; 4.85; 4.69; 4.47; 4.99; 5.14; 4.68; 4.91; 5.03; 4.71; 4.57; 4.94; 4.96; 4.97; 5.25; 4.72; 5.06; 4.78; 4.36; 5.00; 4.87; 4.53; 4.06; 4.00; 4.39. Data set Enter numbers separated by “ ; ". Maximum number of characters: 1000 percentile P % 0 ≤ P ≤ 100 share Share a link to this calculator, including input parameters TWITTER FACEBOOK 9000 Definition 1 Definition 2 Definition 3 Enter the data set and percentile and click the Calculate button. Description and examples Percentile (also called percentile, percentile and centile in different sources and versions of programs) is a statistical measure that indicates the value that a given random variable does not exceed with a specified probability. For example, the phrase "95th percentile is 7" means that 95% of all measured values do not reach the value of 7 and only 5% of all measured values exceed this value. When a service provider for placing client equipment in a data center, connecting it to power supply and communication channels (colocation) issues a monthly invoice for payment of services based on 95th percentile (English bustable billing), which means that the provider cuts off 5% of peak traffic values per month. This calculation method allows users to have short periods of very high traffic, perhaps dozens of times higher than "regular" traffic, at no extra charge. If billed monthly, then users can have very high traffic (within the allocated bandwidth) for 24 × 30 × 0. 05 = 36 hours at no additional charge. An example of such traffic is shown in the figure below. nine0004 Percentiles are also often used by pediatricians to estimate children's height compared to World Health Organization (WHO) statistics for weight, height and head circumference. The percentile value allows you to compare the head circumference, weight and height of the child with the data of other children. For example, the 60th percentile of height means that the girl is taller than 60% of other girls and shorter than 40% of other girls. Definitions It is interesting to note that although we often use percentiles, there is no universal definition for this term. Here we will give three percentile definitions, one simple and two not so simple, since they use linear interpolation. Other definitions of percentile can be found in the literature. Calculations by all definitions give similar results if the number of values in the observational data is large. If the number of values is small, then the results can be quite different. nine0004 Definition 1 According to the first definition, the P th percentile of a list of N numbers ordered by magnitude (from smallest to largest) is the smallest number in the list that is greater than N percent of all numbers of the series under study. For example, in the children's height example above, the 60th percentile means a height that is greater than the height of 60% of other children. This definition uses the nearest rank method. Note that any value calculated by this method will always be present in the original data set. To calculate the percentile, you need to arrange the values in the data set in order from smallest to largest and assign 9 to each value in the data set0024 serial number (rank) . Then the sequence number n is calculated for the given percentile using the formula: The notation ⌈x⌉ means that the result is rounded up to the nearest whole number. This rounding is also called the ceiling. For example, results of 2.2 and 2.7 will be rounded up to 3. After that, the percentile value v is taken from the values sorted in order by ordinal number n . nine0004 The 100th percentile is defined as the largest value in the original dataset. Definition 2 This and the following definitions use linear interpolation between adjacent values in the data set to improve accuracy. This is done instead of rounding to an integer value according to the first definition. There are several variants of this method. Here we will consider only two of them, which are used in MS Excel, starting from version 2010, and in some other programs. nine0024 The fractional ordinal x is calculated using the following formula: In versions of Excel older than 2010, this formula is used in the PERCENTILE.INC() function (English version), which is called PERCENTILE.INC() in the Russian version. This is a function that returns results for the entire range of values 0 ≤ P ≤ 1. If P = 1, PERCENTILE.INC() returns the highest value of the dataset, and if P = 0, then PERCENTILE.INC() returns the low value of the dataset. nine0004 To obtain the serial number n , the result of the calculation according to the above formula is rounded down to the nearest whole number down, that is, to a number that does not exceed the rounded value. For example, the results 2.2 and 2.7 will be rounded up to the ordinal of the value from the input dataset n = 2. The fractional part { x } of the result of calculating the fractional ordinal x is then used to further calculate the percentile value nine0020 v by two adjacent values from the original data set: values with the calculated sequence number v _n and the next higher value v _n+1 : where by definition is the fractional part Below is an example of the calculation for definition 2. definition 3 According to this definition, to calculate the fractional serial number x , a different formula is used than that used for definition 2: In versions of Excel older than 2010, this formula is used in the PERCENTILE. EXC() (English version) and PERCENTILE.EXC() (Russian version) functions. This function throws an error if P is outside the valid range for the given source data set. This means that PERCENTILE.EXC() only interpolates if the value of the specified percentile is between two values in the original dataset. If the function cannot interpolate, it returns an error. For example, if the dataset contains 10 values, you cannot get a result for a percentile value less than 10% and greater than 90%. At the same time, the PERCENTILE.INC() function, by its second definition, will produce a valid result in this situation. As in definition 2, the result is rounded down to the nearest whole number, that is, to a number that does not exceed the rounded value. For example, the results 2.2 and 2.7 will be rounded up to the ordinal value from the input dataset n = 2. As in definition 2, the fractional part { x } of the result of calculating the fractional ordinal x is then also used to further calculate the percentile value v for two adjacent values from the original data set: the value with the calculated sequence number v _n and the next higher value v _n+1 : where by definition of the fractional part Examples of calculating percentiles the methods described above. The values in the dataset are ordered from smallest to largest, and each is assigned a rank from 1 to 12. We will run a calculation on the three definitions and compare the results of our calculations. nine
24	10
29

Calculation according to method 1

Determined order wound N by determination of 1 for 40 percentage :

Since the ordinal rank n is not an integer, we round it up to n = 5. From Table 1, the 40th percentile value for n = 5 is 11.

Calculation according to method 2

This method is an alternative to the nearest rank method. It uses linear interpolation between adjacent values in the dataset. Fractional rank x is calculated using the following formula:

Rank n = 5 percentile v for two adjacent values from the original data set: values with the calculated sequence number v _n and the next higher value v _n+1 :

Calculation by this method08

is another alternative to the nearest rank method. It uses linear interpolation between adjacent values in the dataset. Determine the fractional serial number x :

Ordinal rank n = 5. The fractional part { x } = 0.2 of the result of calculating the fractional ordinal x is then used to further calculate the percentile value v for two adjacent values from the original dataset: values with the calculated ordinal v _n followed by a higher value v _n+1 :

View these examples in a calculator.

Payment method by 9The 5th percentile is the industry standard method for measuring bandwidth (bandwidth) of a link used by ISPs and data centers.

Using percentiles

95th percentile billing method

95th percentile billing method is an industry standard method for measuring bandwidth (capacity) of a channel used by ISPs and data centers. The method allows users to dramatically increase traffic for 5% of the time without increasing the cost of paying for data center services. The method is based on peak load accounting and is commonly used for billing traffic for equipment installed in data centers. nine0004

This graph shows the ISP channel load statistics measured over 32 hours.
1. Average outgoing traffic 2.9 megabits per second (Mbps).
2. 95th percentile outbound 4.1 Mbps.
3. Maximum outgoing traffic 5.7 Mbps.
4. Filtered traffic peaks are not taken into account in the billing calculation.
Because the 95th percentile is 4.1 Mbps, in this example the ISP is billing 5 Mbps because it has a 1 Mbps increment. This should be taken into account when determining the cost of services. If 9The 5th percentile was 3.9 Mbps, this ISP would have billed 4 Mbps.

Most ISPs use a five-minute sampling interval to record traffic and then calculate usage at the 95th percentile. Sometimes providers offer a 90th percentile calculation in order to attract more customers. The average channel width during the sampling interval represents the value of the data set, which is calculated as the number of megabits transmitted through the communication port divided by the length of the five-minute sampling interval (300 seconds). During the monthly period for which the customer is billed, there will be about 9 such values in the calculation datasetthousand. This data set is then sorted as described above and the top 5% of the data with the most traffic is discarded. The value of the 95th percentile is indicated on the invoice, but only if it exceeds the guaranteed bandwidth of the channel specified in the contract and paid by the client in any case, even if the real traffic is less than this bandwidth, since the guaranteed bandwidth is usually included in the cost of operating a rented or own server in the data center. nine0004

Based on this model, high traffic for 24 hours × 30 days × 0.05 = 36 hours is not included in the monthly bill. To determine the 95th percentile, it is common to consider both outgoing and incoming traffic.

Data center customers who pay for its services at the 95th percentile can pay per megabit of regularly used bandwidth and at the same time, if necessary, can dramatically increase traffic for short periods of time without financial consequences.

In this monthly traffic example, the data center customer pays for the 95th percentile, which is only about 4.5 Mbps. At the same time, the peak traffic is 95 Mbps and it is not taken into account when calculating the payment, since these periods are short.

Child body mass index, weight and height

Body mass index (BMI) is defined as the ratio of body mass in kilograms to the square of height in meters and is usually expressed in kg/m² even in the few countries where traditional units of measurement are still used . The body mass index characterizes people into groups of underweight (up to 18.5 kg/m²), normal weight (8.5–25 kg/m²), overweight (25–30 kg/m²), and obesity (over 30 kg/m²). nine0004

Children with a weight between the 5th and 85th percentile are classified as normal weight

In children and adolescents, body mass index is defined differently. The calculation uses the same formula as for adults, but the categorization is different: instead of being compared to several fixed thresholds (underweight, normal weight, overweight, and obese), BMI is compared to the percentile value for children of the same sex, age and living in the same country. For example, the phrase “a girl has a body mass index of the 40th percentile” means that 40% of girls of the same age have a lower body mass index. Children with a BMI below the 5th percentile are considered to be underweight for their age, while those with a BMI between the 5th and 85th percentile are considered to be of normal body weight. Those with a BMI between 85 and 9The 4th percentile is considered overweight and over the 94th percentile is considered obese.

Pediatrics often use the weight and height of a child to assess their physical development compared to growth charts that show the averages and percentiles for children of different ages and sex for a given country.

Of course, body mass index can hardly be called an ideal indicator. It does not take into account many factors of physical development, such as the mass of adipose tissue and muscles and body type. BMI may misinterpret an athlete with a large muscle mass as overweight and at the same time not note the disadvantage of a person with excessive body fat mass, who, despite a normal body mass index, belongs to a group of people with an increased risk of cardiovascular diseases, diabetes type 2 and premature death. nine0004

Percentile scores in education

Another common example in Western education is percentile test scores, which are the percentage of performance below a given target. Test scores in the form of percentiles can often be found in the reports that schools provide to parents. For example, if a student ranks in the 60th percentile, this means that the student did better than 60% of the other students. In other words, this result is better than the average and means that the student studied well. Percentile results for students or students who take a test or exam allow you to compare the performance of an individual student with other students in the comparison group. nine0004

Test results in percentile form can often be found in the reports that schools provide to parents.

Author of the article: Anatoly Zolotkov

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Percentiles in infants and children, what are they for? How are they calculated?

As a child grows throughout their childhood, when they go to the pediatrician, they check growth charts to see if physical development is optimal for their age. Growth charts or percentiles help clinicians and parents evaluate and monitor their child's growth. Although growth charts can provide important information, this information should not be the only diagnostic tool a clinician uses. Percentiles are an analysis of information, but each child is different and does not always have to be accurate for everyone. nine0004

Index

1 What are percentiles?
2 Children's percentiles
3 Children's percentiles
4 How to calculate percentiles
5 Children's percentile chart
6 Girls' percentile chart

What are percentiles?

Percentiles are growth curves or charts that measure and compare children's height. regarding general and standard data. These parameters show height, weight and head circumference, which are considered normal at a certain age, taking into account, first of all, the first years of a baby's life. But it should be noted that every child is a world, and that the doctor himself will evaluate whether the boy or girl is really within the normal range or if there is something to be considered regarding their health. nine0004

Growth curves contain a set of percentiles ranging from 5 to 95%. Doctors measure the circumference of the child's head, in children under 3 years old - weight and height. After collecting this data, the doctor plots the growth according to the child's age.

Weight, height and head circumference, if they fall within the graph, will indicate the percentile. This is adequate. Percentiles are a way to compare your child to other children. Higher percentages indicate a fatter or taller child, while lower percentages indicate a lighter or shorter child. nine0004

For example, a girl with the 75th weight percentile would be over 75 out of 100 girls and under 25 out of 100 girls. Percentiles also allow the clinician to compare height and weight to determine proportionate height. A child with a 90th percentile weight and 25th percentile height is likely to be too heavy for their height; whereas a child with the 50th percentile of height and weight has a good ratio.

Childhood Percentiles

If you want to know if your child's percentiles match their birth age, the first thing you need to do is Consult your pediatrician to determine suitable parameters. . The best percentile charts are the ones your pediatrician will have as they are likely to be based on the WHO charts. The percentile will display your child's weight or height on the growth chart (he may be above or below average), and you have nothing to worry about as they are standard values and everything is fine unless your pediatrician sees something unusual. ordinary, in which case they will have to tell you about it. nine0004

The growth of infants and children is influenced by many external factors, such as feeding or movement, but there is also a great deal of genetic influence. Even if your child or toddler is above or below the standard height, if they are happy, alert, active and in good health, they will rarely suffer from problems. Percentile charts should only be a guide for you, but your pediatrician will always evaluate your child's growth, development, and health.

Percentile children

The same happens with infant percentiles in infant percentiles are indicative values  and should not be of any concern. Although, if a child may be obese for his age, it would be wise for parents to take action in his life, not only because of what they invest in the percentile, but also for the good of his health.

Si the doctor appreciates that parents should take some action In particular, thanks to the data in the growth chart and the data that your child has regarding his weight, height and age, they will immediately inform the parents in order to find the best health solutions baby. nine0004

How to calculate percentile

Childhood obesity is a serious problem Millions of children in our society are overweight. Children under 6 years of age are overweight due to malnutrition and a sedentary lifestyle. Obesity can cause developmental and health problems in children, and percentiles can be a great tool to determine if a child is on the path to becoming obese.

But in addition to physical health problems, there can also be emotional health problems that lead to low self-esteem in children when they feel that their body image is negative. nine0004

You can find calculators online to automatically calculate your children's percentile, but you can also do it yourself with or without the help of a doctor. To calculate the percentile, you must first calculate your BMI (body mass index), where will give you your ideal weight based on your current weight and height. You must remember that BMI does not calculate body fat, but only adequate weight based on height.

BMI is calculated by dividing weight by height in meters squared. nine0423 . For example, if your three-year-old son weighs 16'250 kg and is 92 cm tall, his BMI would be 19'19. The equation to get the BMI would be 16'250 / (0 x 92). Knowing the BMI is not enough to know if a child is overweight, we must take into account the age and whether it is a boy or a girl.

After calculating the BMI, you should look at the growth chart of boys or girls according to the age presented by WHO, after which you can get the percentile corresponding to your son / daughter. Percentiles are an indicator that will help you recognize the relative position of your BMI in relation to your peer group. The average percentile will indicate normal weight, but the lower the risk of weight loss in a child and the higher the risk of being obese or overweight. nine0422 WHO classification of children:

Percentile less than 5: underweight
Percentile 5 to 85: normal weight.
85 to 95 percentile: overweight.
Over 95 percentile: obesity

BMI values would be: