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 is the Average BMI in the UK?
The average BMI in the UK is approximately 27.6 for adults, which falls into the overweight category according to NHS guidelines. This means the majority of UK adults weigh more than the healthy BMI range of 18.5 to 24.9. Understanding how your personal BMI compares to the UK average, and what the NHS considers healthy, can help you assess your own health status and make informed decisions about weight management.
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 BMI and NHS Categories Explained
According to recent UK health data, the average BMI for UK men is approximately 27.9, whilst the average BMI for UK women is around 27.4. Both figures fall firmly into the overweight category rather than the healthy weight range. The NHS BMI categories are: Underweight (below 18.5), Healthy weight (18.5–24.9), Overweight (25.0–29.9), Obese Class I (30.0–34.9), Obese Class II (35.0–39.9), and Severely obese (40.0+).
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds due to increased health risks at the same BMI level. For these groups, a healthy BMI range is 18.5–22.9, and overweight begins at 23.0. Use our free BMI calculator above to check where your personal BMI falls within these NHS ranges instantly.
It's important to remember that whilst the bmi formula (weight in kg divided by height in metres squared) is a useful screening tool, the average BMI alone doesn't tell the whole story about population health. Regional variations exist across the UK, with some areas showing higher average BMIs than others.
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.
BMI Limitations and What Else Matters
Although BMI is widely used by the NHS and public health organisations, it has significant limitations. BMI does not distinguish between muscle and fat—athletes or very muscular individuals may have a high BMI despite low body fat. Age, gender, and ethnicity all affect how BMI relates to actual health risk.
The NHS recommends using BMI alongside waist circumference measurements and other health indicators for a complete picture. A healthy waist measurement is under 94cm (37 inches) for men and under 80cm (31.5 inches) for women. Your GP can assess your individual health risk based on your BMI, family history, lifestyle, and any existing health conditions rather than relying on the average BMI alone.
- 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 an average BMI of 27.6 healthy?
No. The UK average BMI of 27.6 falls into the overweight category. The NHS considers a healthy BMI to be between 18.5 and 24.9. Whilst being average doesn't mean unhealthy, it does suggest many UK adults would benefit from modest weight loss for improved health outcomes.
What's the difference between average and healthy BMI in the UK?
The average UK BMI is around 27.6 (overweight), whilst a healthy BMI according to NHS guidelines is 18.5–24.9. This means the average adult weighs more than what health authorities recommend. However, health is individual, and your GP can advise on what's healthy for you personally.
How do I calculate my BMI and compare it to the UK average?
Divide your weight in kilograms by your height in metres squared. For example, if you weigh 70kg and are 1.73m tall: 70 ÷ (1.73 × 1.73) = BMI of 23.4. Try our free BMI calculator on this page to work it out instantly and see how you compare.
Do different ethnic groups have different healthy BMI ranges in the UK?
Yes. The NHS recommends lower BMI thresholds for adults of South Asian, Chinese, Black African, and Black Caribbean heritage because these groups have higher cardiovascular and diabetes risk at the same BMI. For these groups, healthy BMI is 18.5–22.9, not 18.5–24.9.
Why is the UK average BMI in the overweight category?
Multiple factors contribute: sedentary lifestyles, increased calorie intake, processed foods, stress, and sleep deprivation. About 63% of UK adults are overweight or obese. Public health campaigns and NHS weight management programmes aim to support healthier weight ranges across the population.
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.