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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Weight and BMI Table for UK Adults
A weight and BMI table shows how your weight relates to your height and what health category you fall into according to NHS guidelines. This guide explains the BMI formula, the official NHS BMI ranges for UK adults, and what different BMI categories mean for your health. Whether you're checking your healthy weight range or understanding your current BMI, this table provides the context you need. Use our free BMI calculator above to find your personal BMI instantly, or read on to understand how BMI works and what the numbers mean.
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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.
Understanding the NHS BMI Range and Categories
The BMI formula is weight (kg) divided by height in metres squared. According to NHS BMI guidelines, healthy weight for UK adults falls between a BMI of 18.5 and 24.9. A BMI below 18.5 is classified as underweight, while 25.0 to 29.9 is overweight. The overweight BMI threshold starts at 25.0. BMI categories UK include obesity classes: Class I (30–34.9), Class II (35–39.9), and Class III or severely obese (40+).
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower healthy BMI thresholds: 18.5 to 22.9 is healthy weight, and 23.0 to 27.4 is overweight. These lower thresholds reflect higher cardiovascular and metabolic risk in these populations at standard BMI levels. The BMI calculation itself is the same; only the interpretation of results differs.
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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 What Else Matters
BMI limitations are important to understand: BMI does not distinguish between muscle and fat. Athletes with significant muscle mass may have a high BMI but low body fat percentage. BMI also ignores where fat is stored—central weight around the stomach carries higher health risk than fat elsewhere. Waist circumference is a valuable complement to BMI: the NHS recommends measuring around your natural waist; for men, over 94cm (37in) indicates increased risk, and over 102cm (40in) indicates high risk. For women, over 80cm (31.5in) shows increased risk, and over 88cm (34.5in) shows high risk. Use our free weight converter to track changes in your measurements, and combine BMI assessment with your GP's overall health evaluation for a complete picture.
- 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 a healthy BMI range according to NHS guidelines?
For most UK adults, a healthy BMI is between 18.5 and 24.9. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a healthy BMI of 18.5 to 22.9 due to higher health risks at higher BMI levels in these populations.
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. Our free BMI calculator above will do this instantly for you.
What does a BMI of 25 mean according to BMI categories UK?
A BMI of 25.0 falls into the overweight category. This means your weight is above the healthy range for your height. However, BMI alone doesn't determine health—your GP can advise whether lifestyle changes or further assessment is needed.
Why are the NHS BMI thresholds different for South Asian adults?
Research shows that South Asian, Chinese, Black African, and Black Caribbean populations face higher cardiovascular and metabolic disease risk at lower BMI levels. These groups develop type 2 diabetes and heart disease at BMI levels considered "healthy" for European populations.
What are the main BMI limitations I should know about?
BMI doesn't account for muscle mass (athletes may have high BMI but low fat), age-related muscle loss, pregnancy, or where fat is stored. Waist circumference is a useful complement. Always discuss your personal BMI results with your GP for context relevant to your individual health.
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.