Child healthy growth and weight

"How much should my child weigh?" is a common question for parents. Our children are weighed regularly as babies, but as children grow and develop at different rates it's not always easy to tell if they are a healthy weight.

How to check your child is a healthy weight

Measure their BMI

For children and young people aged 2 to 18, you can check their weight by working out their body mass index (BMI) using the NHS BMI calculator.

A child's BMI tells us if their weight is right for their height, and the result is given as a centile (or percentile). For example, a healthy weight result is between the 2nd and 90th centile.

The BMI calculator takes into account age and sex, as well as height and weight.

If you are concerned about your child's weight or growth, contact a GP or school nurse.

Use the NHS BMI calculator

Measure their waist to height ratio

You may also consider measuring your child’s waist to height ratio by using the NHS ‘Calculate your waist to height ratio’ webpage.

This can help you understand the risk of any potential physical health conditions associated with carrying too much weight around the tummy. The NHS ‘How to measure your waist’ video can guide you.

School height and weight checks

Children are weighed and measured at school in Reception and Year 6 as part of the National Child Measurement Programme (NCMP).

Their height and weight are measured and used to calculate their body mass index (BMI). This information is used to plan and provide better services for children and families.

Have you received feedback about your child’s measurement?

If your child's just been measured at school, the feedback can sometimes be surprising, but they're just a snapshot of your child's weight at that moment in time.

You may receive your child’s measurements by post (a feedback letter), or electronically (for example a text message or email) from the team delivering the NCMP in your area.

In some areas, parents or carers may also be offered a phone call to discuss the measurements and what support is available locally.

If you are worried, speak to your GP or school nurse for advice and support. You may also contact the details included in your feedback for advice and support.

How to check your child's measurements

You can use the NHS BMI calculator to check your child’s measurements, and see if it changes as they grow.

You may also consider measuring your child’s waist to height ratio by using the NHS Calculate your waist to height ratio webpage.

This can help you understand the risk of any potential physical health conditions associated with carrying too much weight around the tummy. The NHS How to measure your waist video can guide you.

Should you talk to your child about their measurements?

The information in the feedback is private. Your local NCMP team does not share it with your child. It is also not shared with other children or school staff. It is entirely up to you as their parent or carer, to decide whether to share the information with your child.

Some parents decide to tell their children and talk about the changes they need to make together. Others decide not to, as younger children may be less able to understand, and it might be simpler to make lifestyle changes without talking to them.

If you decide to speak to your child, talking openly about weight can help to build trust and reassure your child that it is not something to feel ashamed about.

Here are some tips that can help you talk about weight:

avoid blame – focus instead on the healthy things you and your family can do
talk about weight in a kind and supportive way
talk about how weight is important for health, energy and what the body can do
teach your child that everyone deserves respect – whatever their body size, shape or ability

Not sure how to start the conversation? The University of Bath’s ‘Talking to your child about weight: a guide for parents and caregivers of children aged 4-11 years’ resource can help.

Overweight (including very overweight)

Children gain weight as they grow and develop and it’s not always easy to know if this growth is healthy or if they are above the expected weight range for their age, sex and height.

It can sometimes be hard to encourage children to eat a healthy diet and stay active.

If you are not already doing so, making changes to their diet and lifestyle like getting them eating well and increasing their activity levels can help keep them healthy as they grow.

How to help your child become a healthier weight

Healthy weight

If your child is growing as expected for their age, sex and height, there are lots of things you can do as a parent to help your child stay at a healthy weight as they grow, if you are not already doing so.

Keep encouraging your child to eat well and move more to help them maintain a healthy weight.

You can also check their BMI every now and then using the NHS BMI calculator to make sure they stay in the healthy range.

Find out more:

How to help your child stay at a healthy weight

Underweight

If you're concerned your child is below the expected weight range for their age, sex and height, take your child to see your GP.

Low weight can occur for a number of reasons and children who have low weight can still be healthy and developing well.  Children are growing quickly, and they can use more energy (calories) than they take in.

If there is a possible problem with your child's diet, your GP can give advice on what will help bring them up to a healthy weight or refer your child to a dietitian.

You can check your child's height and weight to see if they have moved into the healthy range as they grow using the NHS BMI calculator.

Find out more:

How to help your child gain weight

6 ways to help your child with their weight

Small lifestyle changes can make a big difference – try these top tips.

1. Find some support

Speak to your child's school nurse, GP or practice nurse who will help support your family with diet and lifestyle changes if needed.

Find a GP

2. Make some healthier food swaps

There are lots of easy ways to cut back on sugar, salt and saturated fat – get started with our top tips and simple swaps.

Visit Food Facts

3. Eat balanced meals

Find out what a healthy, balanced diet looks like.

See the Eatwell Guide

4. Try some new recipes

Get inspiration to help your family eat well every day.

Browse our healthier recipes

5. Get moving

Try boosting your family's activity levels in 10-minute bursts with our Disney inspired playalong games.

Play a 10 Minute Shake Up game

6. Less screen time, better sleep

Sitting around too much makes it more likely your child will put on weight, and can affect how well they sleep. Sleeping well helps kids develop, stay healthy and perform better at school.

The Sleep Charity: relaxation tips