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
What's the Average Weight Per Age in the UK?
Average weight varies significantly by age, height, and individual factors. According to UK Office for National Statistics (ONS) data, the average adult man weighs approximately 85.7 kg (13st 7lbs) and the average adult woman weighs approximately 71.6 kg (11st 3lbs). However, "average" does not mean "healthy" — your ideal body weight depends on your height, muscle mass, and overall health. Use our free BMI calculator to find your personal healthy weight range based on NHS guidelines.
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.
Average UK Weight by Age Group
Weight naturally increases with age due to changes in metabolism and muscle mass. Here's what ONS data shows for UK adults:
- Ages 16–24: Men average 79.4 kg (12st 6lbs), women 65.2 kg (10st 4lbs)
- Ages 25–34: Men average 84.1 kg (13st 3lbs), women 70.3 kg (11st 1lb)
- Ages 35–44: Men average 87.2 kg (13st 10lbs), women 73.8 kg (11st 8lbs)
- Ages 45–54: Men average 88.5 kg (13st 13lbs), women 75.2 kg (11st 11lbs)
- Ages 55–64: Men average 86.9 kg (13st 9lbs), women 74.1 kg (11st 8lbs)
- Ages 65+: Men average 81.3 kg (12st 12lbs), women 70.8 kg (11st 2lbs)
These figures are observational averages, not health targets. Many people at these weights fall within a healthy BMI range, whilst others may have health considerations regardless of where they fall on this scale.
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 by Height — NHS Guidelines
Rather than focusing on average weight, the NHS recommends using healthy weight range by height as your reference. A healthy BMI sits between 18.5 and 24.9. Using our free weight converter and BMI calculator, you can find your personal healthy weight range instantly. For example, an adult who is 5ft 8in (173cm) tall should aim for a weight between approximately 55–74 kg (8st 10lbs to 11st 10lbs). For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends slightly lower thresholds, starting at BMI 23.0 as overweight, due to higher cardiovascular risk at lower BMI levels.
- 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.
Is average weight the same as healthy weight?
No. Average weight is what people typically weigh; healthy weight is determined by your height and BMI. Someone at average weight may not be in a healthy weight range, and vice versa. Always check your personal healthy weight range using your height and BMI.
What is the healthiest weight for my age?
There is no single "healthy weight for age" — it depends entirely on your height. Use the NHS BMI categories based on your height to find your healthy range. Our free BMI calculator can calculate this instantly for you.
Does weight increase with age naturally?
Yes, weight typically increases slightly with age due to reduced metabolism and changes in muscle mass. However, this doesn't mean weight gain is necessary or healthy. Maintaining an active lifestyle and balanced diet can help keep weight stable as you age.
How do I know if I'm overweight for my age?
Your age doesn't determine if you're overweight — your height does. Calculate your BMI using your weight and height. If your BMI is 25–29.9, you're in the overweight range; 30+, you're in the obese range according to NHS guidelines.
What factors affect my ideal body weight?
Ideal weight is influenced by height (primary factor), muscle mass, bone density, frame size, genetics, and ethnicity. Two people of the same height can have different healthy weight ranges depending on these factors. Your GP can give personalised advice on your ideal weight.
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.