The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
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Height Chart With Age — Understanding UK Growth References
A height chart with age shows the expected range of heights for children and adults at different stages of development. In the UK, healthcare professionals use the UK90 growth reference charts to track whether children are growing at a healthy rate. These charts compare a child's height against thousands of measurements from UK children of the same age and sex. Understanding where your child sits on a growth chart helps your GP identify any potential health concerns early. Most children grow steadily, but growth rates vary naturally between individuals based on genetics, nutrition, and overall health.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
UK90 Growth Charts — What They Show
The UK90 growth reference charts are the standard used by the NHS to monitor children's growth from birth to age 19. These charts display height plotted against age, with curved lines representing different centiles. A centile shows where a child's height falls compared to other children of the same age — for example, if a child is on the 50th centile, their height is taller than 50% of children their age and shorter than 50%. Children typically stay on roughly the same centile throughout childhood, and this consistency is more important than the actual centile number.
Key centile bands on UK growth charts include:
- 2nd centile: Below this suggests possible growth concerns
- 9th, 25th, 50th, 75th, 91st centiles: Typical healthy range for most children
- 98th centile: Taller than average but within normal variation
Your GP or health visitor can assess your child's growth using these charts during routine appointments. Sudden changes in growth rate — crossing centiles upwards or downwards — may warrant further investigation, though natural variation does occur.
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How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
Average Height by Age in the UK
Average UK heights vary significantly by age and sex. At age 5, the average UK girl is around 109 cm (3ft 7in) and the average boy around 110 cm (3ft 7in). By age 10, girls average approximately 137 cm (4ft 6in) and boys 138 cm (4ft 6in). Most rapid growth happens during infancy and the teenage growth spurt — typically ages 10–14 for girls and 12–16 for boys.
For adults, average heights in the UK are approximately 161.6 cm (5ft 3.5in) for women and 175.3 cm (5ft 9in) for men. These averages have increased over the past century due to improved nutrition and healthcare. Individual height is determined by genetics (approximately 70–80%), nutrition, overall health, and hormonal factors. If you're concerned about your child's growth, your GP can provide personalised NHS guidance and arrange growth monitoring if needed.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
What is a healthy height for a child at age 5?
At age 5, average UK heights are around 109–110 cm. However, healthy heights vary widely based on genetics and family background. Your health visitor uses UK90 growth charts to track whether your child is growing well for their own growth pattern. If your child is consistently between the 9th and 91st centiles, they are within a typical healthy range.
Why do children's heights vary so much at the same age?
Height variation reflects genetics (inherited from parents), nutrition, sleep quality, and overall health. Growth is also not always steady — children have growth spurts followed by slower periods. Genetics accounts for about 70–80% of adult height, with the remaining 25–30% influenced by environmental factors like diet and illness.
When do children stop growing?
Most children reach their final adult height by late teens or early twenties. Girls typically stop growing around age 16–17, whilst boys often continue until age 18–19. The growth plates in bones fuse at this point, ending growth. Genetics, nutrition, and overall health during childhood all influence final adult height.
Should I worry if my child is taller or shorter than other children?
Not necessarily. Normal healthy heights span a wide range. What matters more is that your child stays on a consistent centile over time. Sudden changes in growth rate — jumping centiles up or down — warrant discussion with your GP or health visitor, as this can sometimes indicate a health issue worth investigating.
How does UK health guidance assess healthy weight alongside height?
Your GP uses both height and weight together to calculate BMI (body mass index), which helps assess whether weight is healthy for that particular height. In children, BMI is assessed using age and sex-specific growth charts rather than adult categories. Our free BMI calculator can help you understand healthy weight ranges for adults using UK NHS thresholds.
Ready to take control of your weight loss journey?
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