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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Average Height and Weight by Age in the UK
Understanding average height and weight by age helps you see how your measurements compare to UK population data. This guide shows typical heights and weights across different age groups, alongside NHS guidance on healthy weight ranges. Your individual healthy weight depends on your height, age, sex, and overall health — not just where you fall on an average chart. Use this information as a reference point, then check your personal BMI and health context with our free tools to get a clearer picture of what's healthy for you.
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Calculate Your BMI Instantly
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.
Average Height and Weight by Age Group in the UK
UK population averages vary by age and sex. Adult men average around 175.3 cm (5ft 9in) tall and weigh approximately 85.7 kg (13st 7lbs), giving an average BMI of 27.9. Adult women average 161.6 cm (5ft 3.5in) tall and weigh around 71.6 kg (11st 3lbs), with an average BMI of 27.4. These figures come from Office for National Statistics (ONS) data and represent population averages — not targets. Children's heights and weights vary much more widely and follow different growth patterns tracked on NHS growth charts. Teenagers experience rapid growth spurts, so age-specific centile charts are more useful than simple averages for assessing whether a young person is growing healthily.
- Newborns to age 5: Height and weight tracked on NHS growth centile charts — averages are less meaningful due to rapid variation
- Children aged 5–11: Average heights range from approximately 110 cm at age 5 to 145 cm at age 11; weight increases from roughly 18 kg to 38 kg
- Teenagers aged 12–18: Most growth occurs during this period; heights and weights vary significantly by developmental stage
- Adults aged 18–65: Heights relatively stable; weights tend to increase gradually with age
- Adults over 65: Average heights may decrease slightly due to spinal compression; weight changes vary
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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.
How Your Weight Compares to Healthy Weight Guidelines
Average weight is not the same as healthy weight. Since the UK average adult BMI is approximately 27.5 — which falls in the overweight category — being close to the average does not mean your weight is necessarily healthy for you. The NHS defines a healthy BMI as 18.5 to 24.9 for most adults, or 18.5 to 22.9 for those of South Asian, Chinese, Black African, or Black Caribbean heritage. To find your personal healthy weight range, use our free BMI calculator above — it accounts for your specific height and applies NHS guidance. Your healthy weight also depends on factors beyond BMI: muscle mass, where fat is stored (waist circumference matters), age, and any weight-related health conditions. Consulting your GP gives you personalised advice based on your individual health picture rather than population averages.
- 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 average height and weight for UK adults?
According to Office for National Statistics data, the average UK adult man is 175.3 cm (5ft 9in) tall and weighs 85.7 kg (13st 7lbs). The average UK adult woman is 161.6 cm (5ft 3.5in) tall and weighs 71.6 kg (11st 3lbs). However, these are population averages — not health targets. Individual healthy weight varies based on height, age, sex, and health status.
How do I know if my weight is healthy for my height and age?
Check your BMI using our free BMI calculator above — it shows whether your weight falls in the healthy range for your height according to NHS guidelines. A healthy BMI is 18.5–24.9 for most adults (or 18.5–22.9 for certain ethnic groups). Your GP can also assess your health in context, looking at waist circumference, fitness, and any weight-related health conditions.
Why is my weight different from the average if I'm the same age and height?
Weight varies due to genetics, muscle mass, bone density, metabolism, medications, and lifestyle factors. Two people of identical height and age can have different healthy weights. The average is just a reference point — your personal healthy weight depends on your individual health profile, not population statistics.
Are children's weights and heights the same as adult averages?
No. Children grow at different rates, and their healthy weight ranges are tracked using NHS growth centile charts specific to their age and sex — not adult categories. A child's height and weight should be assessed by their health visitor or GP using age-appropriate growth charts, not adult BMI or average figures.
How can I convert my weight to check against UK averages?
Use our free weight converter on this page to switch between kg, stone, and pounds. Once you've converted your weight, use our BMI calculator to see how your weight compares to NHS healthy weight guidelines for your specific height, rather than just comparing to population averages.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.