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
Free tracker included with every download this week
Average Weight to Age — UK Data & Healthy Weight Ranges
Average weight varies significantly by age, sex, and individual factors. In the UK, the average adult man weighs approximately 85.7 kg (13 stone 7 lbs) and the average adult woman weighs approximately 71.6 kg (11 stone 3 lbs). However, average weight is not the same as healthy weight. The NHS defines healthy weight using BMI categories, which take both weight and height into account. This guide provides UK reference data and helps you understand what a healthy weight range means for your age and height.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
UK Average Weight Data by Age & Sex
According to Office for National Statistics (ONS) data, UK average weights show clear patterns across age groups:
- Ages 19–34: Men average 82 kg (12 st 13 lbs); women average 68 kg (10 st 9 lbs)
- Ages 35–54: Men average 87 kg (13 st 10 lbs); women average 73 kg (11 st 6 lbs)
- Ages 55–74: Men average 86 kg (13 st 8 lbs); women average 74 kg (11 st 9 lbs)
- Ages 75+: Weight typically decreases due to muscle loss and changes in body composition
These figures represent average weight only. A person at average weight may not necessarily be at a healthy weight—that depends on their height and overall health. Use our free BMI calculator above to determine whether your weight falls within the healthy weight range for your height.
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.
Healthy Weight Range vs. Average Weight
Average weight and healthy weight are different measurements. Average weight is what most people weigh; healthy weight is what the NHS recommends based on height and health risk factors. A healthy weight range for any height is calculated using BMI (body mass index). For example, at 5 feet 8 inches (1.73 m), the healthy weight range is approximately 55.4 to 74.5 kg (8 st 10 lbs to 11 st 10 lbs). Many UK adults weigh above this range, which is why average weight is often higher than healthy weight. Age alone doesn't determine healthy weight—height and individual health factors matter more. Try our free weight converter above to see your weight in both metric and imperial measurements.
- 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 weight for a UK adult?
According to ONS data, the average UK man weighs approximately 85.7 kg (13 st 7 lbs) and the average UK woman weighs approximately 71.6 kg (11 st 3 lbs). However, these are averages, not recommendations for healthy weight, which depends on height and health factors.
Does healthy weight change with age?
Healthy weight ranges (defined by BMI) remain the same across adult ages: BMI 18.5–24.9 is healthy for all adults. However, maintaining muscle mass becomes more important with age, and some health conditions become more common in older adults, affecting individual weight management approaches.
How do I calculate healthy weight for my height?
Use our free BMI calculator on this page to find your healthy weight range instantly. Alternatively, multiply your height in metres by itself, then multiply by 18.5 and 24.9. The results show your healthy weight range in kilograms.
Why is my weight higher than average but my BMI is healthy?
This often happens if you have more muscle mass than average—muscle is denser than fat. BMI doesn't distinguish between muscle and fat, so two people at the same weight and height may have very different body compositions. Your GP can discuss individual health context.
Should I aim for average weight or healthy weight?
Aim for a weight within the healthy BMI range (18.5–24.9) for your height, not average weight. The NHS healthy weight range is based on health risk, not what most people weigh. Your individual healthy weight also depends on factors like muscle mass, medical history, and ethnicity.
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.