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 27โ28 for both men and women, according to the latest Office for National Statistics data. This puts the average UK adult in the overweight category, above the NHS healthy weight range. Understanding where the UK population sits on the BMI scale, and where you fit personally, can help you make informed decisions about your health. Check your own BMI instantly using our free BMI calculator above to see how your measurement compares to national averages and NHS guidelines.
10,000+ calculations today ยท NHS-aligned thresholds ยท 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/mยฒ).
While BMI isn't a perfect measure โ it doesn't account for muscle mass, bone density, or fat distribution โ 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 โ 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 BMI Across the UK Population
Based on recent Office for National Statistics (ONS) data, the average BMI for UK men is approximately 27.9, whilst women average around 27.4. Both figures sit firmly in the overweight category according to NHS standards (BMI 25โ29.9). The average UK man weighs about 85.7 kg (13st 7lbs) at a height of 175.3 cm (5ft 9in), whilst the average woman weighs 71.6 kg (11st 3lbs) at 161.6 cm (5ft 3.5in).
This means the majority of UK adults are technically overweight by BMI measurement, though BMI alone doesn't account for muscle mass or individual health factors. Around 63% of UK adults are overweight or obese (BMI 25+), with approximately 28% meeting the definition of obese (BMI 30+). Use our weight converter to check your own weight in stone, lbs, or kg, then calculate your personal BMI to see where you stand relative to these national averages.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care โ 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 โ 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 โ completely free.
BMI Limitations and What Matters More
Whilst knowing the average BMI in the UK provides useful context, it's important to understand that BMI has significant limitations. BMI does not distinguish between muscle and fat โ athletes or people with high muscle mass may have a high BMI despite low body fat. It also doesn't account for where fat is stored; waist circumference is often a better predictor of health risk than BMI alone.
The NHS recommends checking both your BMI and your waist measurement. A healthy waist circumference is under 94 cm (37 inches) for men and under 80 cm (31.5 inches) for women. If your BMI is in the overweight range but your waist is healthy, your individual health risk may be lower than the average suggests.
- 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 โ 5mg โ 7.5mg โ 10mg โ 12.5mg โ 15mg
- GLP-1 receptor agonist
- Up to 15โ17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg โ 0.5mg โ 1mg โ 1.7mg โ 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 | 15โ22.5% | 12โ17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20โ32 weeks | 16โ20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | ยฃ150โยฃ250/month | ยฃ150โยฃ300/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 โ 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 27โ28 healthy in the UK?
No. The NHS healthy BMI range is 18.5โ24.9. An average of 27โ28 places most UK adults in the overweight category. This reflects rising obesity rates in the UK population, not a healthy standard. Your individual healthy BMI depends on your height and age, not population averages.
What is considered a healthy BMI according to NHS guidelines?
The NHS defines healthy weight as a BMI between 18.5 and 24.9 for most adults. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a slightly lower range of 18.5โ22.9 due to higher health risks at the same BMI. Your GP can advise what's healthy for you personally.
Why is the average UK BMI so high compared to healthy ranges?
The UK has rising rates of overweight and obesity due to multiple factors: sedentary lifestyles, increased calorie-dense food availability, portion sizes, and reduced physical activity. About 63% of UK adults are overweight or obese, which raises the population average well above the healthy BMI range recommended by health authorities.
Should I worry if my BMI is close to the UK average?
Being close to the population average doesn't mean your health is fine. The average doesn't equal healthy. If your BMI is 25 or above, discuss it with your GP, especially if you have weight-related health conditions like high blood pressure, type 2 diabetes, or sleep apnoea. Your GP can assess your individual risk.
How accurate is BMI for measuring health?
BMI is a useful screening tool but has real limitations. It doesn't account for muscle mass, bone density, age, or where fat is stored. Waist circumference, fitness level, and metabolic health are also important. Use our BMI calculator as one indicator, but always discuss your personal health with your GP for a complete picture.
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.