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 — NHS UK Standards
A BMI chart by height and weight helps you quickly understand whether your weight falls into a healthy range according to NHS guidelines. Your BMI (body mass index) is calculated from your height and weight, and the NHS uses specific categories to classify whether you're at a healthy weight, overweight, or obese. This guide explains how to read a BMI chart, what the NHS recommends, and what your results mean for your health. Use our free BMI calculator above to find your personal BMI instantly, or read on to understand the full picture.
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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 Healthy Weight Ranges
The NHS BMI formula divides your weight in kilograms by your height in metres squared. The resulting number places you into one of five categories that guide health recommendations in the UK.
According to NHS BMI guidance, these are the standard categories for adults:
- Below 18.5: Underweight — may indicate insufficient nutrition
- 18.5 to 24.9: Healthy weight — the target healthy BMI range for most adults
- 25.0 to 29.9: Overweight — increased health risks begin to rise
- 30.0 to 34.9: Obese (Class I) — significant health risks
- 35.0 to 39.9: Obese (Class II) — higher health risks
- 40.0 and above: Severely obese (Class III) — greatest health risks
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds — healthy weight is 18.5 to 22.9, and overweight begins at 23.0. This is because these groups face higher cardiovascular and diabetes risk at lower BMI levels. The BMI range UK standard may also be adjusted by your GP based on your individual health profile, age, and muscle mass.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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
The NHS offers a structured approach to weight management across four tiers. Tier 1 includes self-help using tools like the NHS Weight Loss Plan and digital programmes. Tier 2 involves your GP and community weight management services with behaviour change support. Tier 3 provides specialist multidisciplinary weight management services where prescription weight loss medications may be considered. Tier 4 is bariatric (weight loss) surgery for severe obesity with serious health complications.
If your BMI is consistently above 25, or if you have weight-related health conditions like high blood pressure, type 2 diabetes, or sleep apnoea, speak to your GP. They can assess your individual health, discuss your BMI in context, and recommend the right support pathway for you. Remember, BMI limitations exist — it doesn't account for muscle mass or where fat is stored — so your GP may consider additional measurements like waist circumference.
- 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's the difference between my BMI and healthy weight range?
Your BMI is a single number calculated from your height and weight. Your healthy weight range is the band of weights that produce a BMI between 18.5 and 24.9 for your specific height. For example, at 5ft 8in (173cm), a healthy weight range is roughly 55–74kg. Use our free BMI calculator to find both your current BMI and your personalised healthy range.
Why does the NHS have different BMI categories for some ethnic backgrounds?
Research shows that people of South Asian, Chinese, Black African, and Black Caribbean descent have higher risk of type 2 diabetes and cardiovascular disease at lower BMI levels. The NHS recommends these groups use a healthy BMI range of 18.5–22.9 instead of 18.5–24.9. Your GP can advise if adjusted thresholds apply to you.
Are there limitations to using a BMI chart?
Yes. BMI doesn't distinguish between muscle and fat — athletes may have high BMI but low body fat. It also doesn't account for where fat is stored (belly fat is riskier). The NHS recommends also measuring waist circumference: over 94cm (men) or 80cm (women) indicates increased risk. Your GP can provide a full health assessment beyond BMI alone.
What should I do if my BMI falls into the overweight or obese category?
Start by speaking to your GP, who can assess your individual health, discuss any weight-related conditions, and recommend the right support. Options range from self-help digital tools (Tier 1) to community programmes (Tier 2) to specialist services (Tier 3) where prescription weight loss medication may be considered. Track your progress using our free progress tracker.
How accurate is a BMI chart compared to the BMI calculator?
A BMI chart gives an approximate range, while a BMI calculator provides your exact BMI. Charts are useful for quick reference, but for precision — especially if you're near a category boundary — use our free BMI calculator above. Both are based on the same NHS formula and will give you the same category outcome.
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.