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 by Height and Weight Chart
A BMI chart shows you where your height and weight fall within NHS health categories — from underweight through to severely obese. Your BMI (body mass index) is a screening tool that helps identify whether your weight is in a healthy range for your height. This guide explains how to read a BMI chart, what the different ranges mean, and why BMI is useful but has limitations. You can also calculate your personal BMI instantly using our free BMI calculator above to see exactly where you fall on the chart.
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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.
How to Read a BMI Chart and NHS Weight Categories
BMI is calculated using a simple formula: weight in kilograms divided by height in metres squared (kg/m²). A BMI chart displays this across different heights and weights, showing which category each combination falls into. The NHS defines five BMI categories for adults:
- Underweight: Below 18.5
- Healthy weight: 18.5 to 24.9
- Overweight: 25.0 to 29.9
- Obese (Class I): 30.0 to 34.9
- Obese (Class II): 35.0 to 39.9
- Severely obese (Class III): 40.0 and above
For example, at 173cm (5ft 8in) tall, a healthy weight range is approximately 55–75kg (8st 10lbs to 11st 10lbs). Adults of South Asian, Chinese, Black African, or Black Caribbean heritage have lower recommended thresholds — the healthy range starts at 18.5 and overweight begins at 23, reflecting higher cardiovascular risk at lower BMI levels in these populations.
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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 Why Waist Measurement Matters Too
While a BMI chart is a useful screening tool, BMI does not distinguish between muscle and fat. Athletes, weight trainers, and very muscular individuals may have a high BMI but low body fat percentage. BMI also ignores where fat is stored — central fat (around the stomach) carries greater health risk than fat distributed elsewhere. The NHS recommends measuring waist circumference alongside BMI: men over 94cm (37in) have increased health risk, and women over 80cm (31.5in) have increased risk. For a complete picture of your health, discuss your BMI chart reading with your GP, who can consider your overall fitness, family history, and any weight-related health conditions.
- 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 according to the NHS?
A healthy BMI range is 18.5 to 24.9 for most UK adults. However, adults of South Asian, Chinese, Black African, or Black Caribbean heritage have lower thresholds — the healthy range is 18.5 to 22.9 due to increased metabolic risk at higher BMI levels. Your GP can advise what's healthy for you personally.
How do I find my BMI on a height and weight chart?
Locate your height on the left side of the chart and your weight along the top, then find where they intersect. That cell shows your BMI and category. Alternatively, use our free BMI calculator above — it's faster and gives your exact BMI instantly.
Can BMI be inaccurate?
Yes. BMI doesn't account for muscle mass, bone density, or fat distribution. Very muscular people may have high BMI but be healthy. BMI is also less accurate for elderly people, during pregnancy, or in children. It's a screening tool, not a diagnostic tool — always discuss your results with your GP.
What BMI is considered overweight?
A BMI of 25.0 to 29.9 is classified as overweight by the NHS. However, even being in the overweight range can increase risk of type 2 diabetes and cardiovascular disease. Weight-related health conditions may develop at lower BMI for some individuals, especially those of South Asian or Black African heritage.
Should I try to reach a specific BMI?
Rather than targeting a specific BMI number, focus on reaching a healthy BMI range (18.5–24.9) that feels sustainable for your lifestyle. Even a 5–10% reduction in body weight can bring significant health benefits. Your GP or a weight management specialist can help set realistic targets based on your individual health profile and circumstances.
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.