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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Adult BMI Chart — Find Your Healthy Weight Range
An adult BMI chart shows where your weight falls on the NHS scale and whether it's in a healthy range for your height. BMI (body mass index) is a simple screening tool that divides your weight in kilograms by your height in metres squared. The resulting number places you in one of five categories: underweight, healthy weight, overweight, obese, or severely obese. Our free BMI calculator above will work this out instantly for you, but understanding the bmi range uk uses helps you make sense of your personal health context at a glance.
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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 BMI chart divides adults into five main categories based on clinical risk. A healthy BMI sits between 18.5 and 24.9 — this is where health risks related to weight are lowest. An overweight bmi threshold starts at 25.0, classified as overweight until 29.9. From 30.0 onwards, the chart shows obesity in three classes: Class I (30–34.9), Class II (35–39.9), and Class III (40+, severely obese).
If your BMI is below 18.5, you're classified as underweight, which also carries health risks including weakened bones and reduced immunity. The bmi formula used is straightforward: weight (kg) ÷ height (m)². For example, someone 1.73m tall weighing 70kg has a BMI of around 23.4, falling comfortably in the healthy range. However, bmi limitations exist — the formula doesn't distinguish muscle from fat, so athletes or very muscular individuals may have a higher BMI without excess body fat.
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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.
Important Limitations and What to Consider Alongside BMI
While the adult bmi chart is useful for screening, it's not the complete picture of health. BMI doesn't account for where fat is stored — excess weight around the waist (apple shape) carries higher cardiovascular risk than fat distributed elsewhere. The NHS recommends checking your waist circumference too: over 94cm for men and 80cm for women indicates increased risk. Additionally, bmi categories uk apply differently to people of South Asian, Chinese, Black African, or Black Caribbean heritage, who face higher health risks at lower BMI levels. Your GP can interpret your personal chart results in context of your age, family history, fitness level, and any existing health conditions to give you tailored guidance.
- 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 BMI should adults aim for according to the NHS?
The NHS healthy BMI range for adults is 18.5 to 24.9. This range carries the lowest health risks related to weight. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a healthy BMI between 18.5 and 22.9 due to higher risk profiles at higher BMI levels.
How do I calculate my BMI using the adult BMI chart?
Use the bmi formula: your weight in kilograms divided by your height in metres squared. For example, 70kg ÷ (1.75m)² = 22.9 BMI. You can also use our free BMI calculator above, which does this instantly and shows you where you sit on the NHS chart.
Why do different ethnic groups have different BMI thresholds on the chart?
Research shows that South Asian, Chinese, Black African, and Black Caribbean populations have a higher risk of type 2 diabetes and heart disease at lower BMI levels compared to white European adults. The NHS therefore recommends lower thresholds for these groups to better reflect their individual health risk.
What are the limitations of using an adult BMI chart?
BMI doesn't distinguish between muscle and fat, so athletes may have a high BMI without excess fat. It also ignores where fat is stored, doesn't account for age-related changes, and may be less accurate in older adults or during pregnancy. Always combine BMI with waist measurement and speak to your GP for personalised advice.
Can I use the adult BMI chart if I'm very muscular or an athlete?
The BMI chart may overestimate health risk for muscular individuals because muscle is denser than fat. If you're very fit or athletic, your GP may recommend body composition analysis or waist measurement alongside BMI to get a clearer picture of your actual health status. ```
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.