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 With Age Chart — UK Growth Reference Guide
Understanding height development across different ages is an important part of monitoring children's and adolescents' health. In the UK, the NHS uses standardised growth charts based on the UK90 growth reference, which tracks typical height progression from birth through adulthood. This guide explains what typical height ranges are at different ages, how growth is monitored in UK healthcare, and when variations may warrant discussion with your GP. Height is influenced by genetics, nutrition, overall health, and individual development patterns — not all children grow at the same rate.
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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.
UK Growth Charts and Height Standards by Age
The UK90 growth reference charts are the standard measurement tool used by NHS health professionals to track child and adolescent height development. These charts show the typical range of heights for children at each age, accounting for natural variation in growth rates. Height is measured in centimetres and plotted against age in months or years.
Key height centiles on UK growth charts:
- 2nd centile — below this may indicate slower growth requiring assessment
- 50th centile — median (average) height for that age
- 98th centile — upper range of typical healthy growth
A child's height is considered healthy if it falls between approximately the 2nd and 98th centiles. Small variations in position on the chart between check-ups are normal. Your GP or health visitor will monitor growth trends over time rather than focusing on a single measurement — steady progression along a consistent centile is reassuring, even if growth is slower or faster than average.
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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.
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Average Height by Age — UK Reference Ranges
Approximate average heights for UK children (these are typical values; individual variation is normal):
- Age 5 years: approximately 109 cm (3ft 7in)
- Age 10 years: approximately 138 cm (4ft 6in)
- Age 13 years: approximately 156 cm (5ft 1in)
- Age 16 years: approximately 168 cm (5ft 6in)
Growth rate varies significantly during adolescence, especially during puberty when height can change rapidly. Boys typically experience their growth spurt slightly later than girls (ages 12–16 for boys; 10–14 for girls). Adult height is usually reached by late teenage years, though growth can continue into early adulthood. Your health visitor or school nurse can plot your child's height on official growth charts and discuss normal variation with you.
- 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 the UK90 growth chart and why is it used?
The UK90 is the standard reference chart used by the NHS to track children's height and weight development from birth to 20 years. It's based on measurements from a large, representative sample of UK children and shows typical growth patterns. Health professionals use it to identify whether a child's growth is progressing normally, allowing early identification of growth concerns requiring further investigation.
At what age do children typically reach their adult height?
Most children reach their full adult height by the late teenage years (usually by age 18–20). Growth plates in the bones close during late adolescence, stopping further height increase. Growth during the teenage years is often rapid, particularly during puberty. Individual timing varies significantly, so discussion with your GP or health visitor is important if you have concerns about growth progression.
Why does my child's height fall below or above average?
Height is primarily determined by genetics — children of taller parents typically grow taller. Nutrition, overall health, physical activity, and individual development timing also influence height. Being shorter or taller than the average doesn't necessarily indicate a health problem if growth is tracking steadily along a consistent centile. Your health visitor can advise if assessment is needed.
When should I be concerned about my child's height?
Discuss height concerns with your GP or health visitor if: growth appears to have slowed significantly, your child falls below the 2nd centile, growth has dropped by more than two centile lines, or height seems inconsistent with family patterns. These signs don't always indicate problems, but professional assessment helps identify whether further investigation is needed.
How does height relate to healthy weight in children?
Height is one factor used in paediatric BMI assessment for children. Unlike adults, BMI in children uses age and sex-specific centile charts rather than fixed categories. The NHS Healthy Weight Calculator for children uses both height and weight to determine whether a child's weight is healthy for their age and growth pattern. Always consult a health professional for personalised advice.
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