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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Height Weight BMI Chart — What NHS Guidelines Tell Us
A height weight BMI chart is a simple way to see whether your weight falls within a healthy range according to NHS guidelines. The chart combines your height and weight to calculate your BMI (body mass index), which helps you understand your health risk profile. This guide explains the NHS BMI categories, how to use a BMI chart effectively, and what the NHS recommends if your BMI falls outside the healthy range. Use our free BMI calculator above to find your personal BMI instantly, or read on to understand how NHS charts work and what they mean for your health.
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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 NHS BMI Categories and Thresholds
The NHS uses standardised BMI categories to help adults assess their weight health. BMI is calculated by dividing your weight in kilograms by your height in metres squared (BMI = weight ÷ height²). According to NHS guidance, the standard healthy BMI range is 18.5 to 24.9 for most UK adults. A BMI below 18.5 is classified as underweight, 25.0 to 29.9 as overweight, and 30.0 and above as obese.
However, the NHS recognises that ethnicity affects health risk at different BMI levels. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the recommended healthy BMI range is lower: 18.5 to 22.9. This is because these groups face a higher risk of type 2 diabetes and cardiovascular disease at lower BMI levels than the general population.
- BMI 18.5–24.9: Healthy weight (all populations)
- BMI 25.0–29.9: Overweight
- BMI 30.0–34.9: Obese (Class I)
- BMI 35.0–39.9: Obese (Class II)
- BMI 40.0+: Severely obese (Class III)
It's important to remember that BMI has limitations. It does not distinguish between muscle and fat — an athlete may have a high BMI but low body fat percentage. BMI also doesn't account for where fat is stored, and waist circumference is increasingly recognised as an important health marker alongside BMI.
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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.
NHS Weight Management Pathway and When to Seek Help
If your BMI falls outside the healthy range, the NHS offers a structured weight management pathway. Tier 1 support includes self-help tools, digital programmes, and community weight management services — these are free and available to all. If you need more support, your GP can refer you to Tier 2 services, which typically involve behaviour change programmes and dietetic advice.
For adults with a BMI of 30 or above, or 25–29.9 with weight-related health conditions (such as type 2 diabetes, high blood pressure, or sleep apnoea), your GP may refer you to Tier 3 specialist weight management services. These services can provide prescription weight loss medication alongside dietary and lifestyle support. Use the weight converter on this page to check your weight in different units, and try our GLP-1 weight loss calculator if you're interested in understanding how prescription support might work for you.
- 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.
How do I use a height weight BMI chart?
Find your height on the left axis and your weight on the bottom axis, then locate where they intersect — this shows your BMI category. Alternatively, calculate your BMI using the formula (weight in kg ÷ height in m²) or use our free BMI calculator above. Both methods give the same result and show you which NHS category you fall into.
What is the healthy BMI range according to NHS guidelines?
The NHS defines a healthy BMI as 18.5 to 24.9 for most UK adults. However, for adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a healthy range of 18.5 to 22.9 due to higher health risks at higher BMI levels in these populations.
Does a high BMI always mean I'm unhealthy?
BMI is a useful screening tool but has important limitations. It doesn't distinguish between muscle and fat, so athletes or very muscular individuals may have a high BMI while being fit and healthy. It also doesn't account for where fat is stored. Your GP can assess your individual health risk based on BMI, waist circumference, and other factors.
What should I do if my BMI is above 30?
Speak to your GP, who can assess your individual health and discuss options. If you have weight-related health conditions, your GP may refer you to NHS Tier 3 specialist weight management services, which offer behaviour change support and, where appropriate, prescription medication alongside lifestyle changes.
Are ethnic-adjusted BMI thresholds used in UK clinical practice?
Yes. The NHS recommends lower BMI thresholds for South Asian, Chinese, Black African, and Black Caribbean populations due to evidence that these groups face higher cardiovascular and metabolic disease risk at lower BMI levels. Your GP will use these adjusted thresholds if they apply to you.
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.