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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BMI Table UK — Complete NHS Categories and Healthy Ranges
A BMI table is the fastest way to understand where your weight sits against NHS health guidelines. This BMI table UK uses the standard NHS categories and includes ethnicity-adjusted thresholds for adults of South Asian, Chinese, Black African, and Black Caribbean backgrounds. Use our free BMI calculator above to find your personal BMI instantly, or read on to understand the full BMI range UK and what each category means for your health.
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.
NHS BMI Categories and What They Mean
The NHS uses a BMI formula based on your weight and height to categorise adult health. Your BMI is calculated by dividing your weight in kilograms by your height in metres squared. This gives a number that falls into one of five BMI categories UK:
- Below 18.5 — Underweight
- 18.5 to 24.9 — Healthy weight (the target healthy BMI range for most adults)
- 25.0 to 29.9 — Overweight
- 30.0 to 34.9 — Obese (Class I)
- 35.0 to 39.9 — Obese (Class II)
- 40.0 and above — Severely obese (Class III)
For South Asian, Chinese, Black African, or Black Caribbean adults, the NHS BMI thresholds are lower. The healthy range starts at 18.5 but tops out at 22.9, and the overweight BMI threshold begins at 23.0 — reflecting higher cardiovascular and diabetes risk at lower BMI levels in these populations. Use the BMI calculator on this page to check your personal category instantly.
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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 Complementary Health Measures
While a BMI table is a useful first screening tool, it has important limitations. BMI does not distinguish between muscle and fat — athletes or very muscular individuals may have a high BMI but low body fat. BMI also ignores where fat is stored on your body; abdominal fat carries greater health risk than fat stored elsewhere. Additionally, BMI is less accurate for older adults (who naturally lose muscle mass), pregnant women, and very short individuals.
For a more complete picture, your GP can assess your BMI alongside waist circumference (men over 94cm, women over 80cm signals increased risk), blood pressure, and blood glucose. These together give a much clearer view of your actual health risk than BMI alone.
While a BMI table is a useful first screening tool, it has important limitations. BMI does not distinguish between muscle and fat — athletes or very muscular individuals may have a high BMI but low body fat. BMI also ignores where fat is stored on your body; abdominal fat carries greater health risk than fat stored elsewhere. Additionally, BMI is less accurate for older adults (who naturally lose muscle mass), pregnant women, and very short individuals.
For a more complete picture, your GP can assess your BMI alongside waist circumference (men over 94cm, women over 80cm signals increased risk), blood pressure, and blood glucose. These together give a much clearer view of your actual health risk than BMI alone. Try the weight converter on this page to switch between kg, stone, and lbs if you need to convert your measurements into NHS format.
- 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 healthy BMI range for UK adults?
According to NHS guidelines, a healthy BMI is between 18.5 and 24.9 for most UK adults. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a slightly lower range of 18.5 to 22.9. Your GP can advise on what's healthy for you personally.
How do I calculate my BMI using the BMI formula?
Divide your weight in kilograms by your height in metres squared. For example, if you weigh 70kg and are 1.75m tall: 70 ÷ (1.75 × 1.75) = 70 ÷ 3.06 = 22.9 BMI. Use our free BMI calculator above for gradual improvement.
What does overweight BMI threshold mean?
The overweight BMI threshold is where your BMI reaches 25.0 and above. At this point, you're classified as overweight according to NHS definitions. This doesn't automatically mean your health is at risk — your GP will consider your full health picture, including family history and other risk factors.
Why are there different BMI thresholds for different ethnicities?
Research shows that some ethnic groups — particularly South Asian, Chinese, Black African, and Black Caribbean populations — develop weight-related diseases like type 2 diabetes and heart disease at lower BMI levels. The NHS adjusted thresholds reflect this higher metabolic risk.
Is BMI the only measure of health I need to know?
No. BMI is a screening tool but has limitations. Waist circumference, blood pressure, cholesterol, blood glucose, and physical fitness are equally important. Your GP can assess all these together for a complete health picture rather than relying on BMI alone.
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.