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 Chart in Stone — UK Weight Categories Explained
A BMI chart in stone shows you where your weight falls within NHS health categories. BMI (body mass index) is a simple screening tool that uses your height and weight to estimate whether you're in a healthy weight range. The chart categorises adults into underweight, healthy weight, overweight, and obese ranges. Use our free BMI calculator above to find your personal BMI instantly, then cross-reference it with the categories below to understand what it means 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.
NHS BMI Categories and Stone Weight Ranges
The NHS BMI chart divides adults into five main categories based on their BMI score. Here's how these categories translate to stone and pounds:
- Underweight: BMI below 18.5 — generally below 8 stone 7lbs (55kg) for a 5ft 8in adult
- Healthy weight: BMI 18.5–24.9 — typically 8st 7lbs to 11st 7lbs (55–73kg) for a 5ft 8in adult
- Overweight: BMI 25.0–29.9 — roughly 11st 7lbs to 13st 12lbs (73–88kg) for a 5ft 8in adult
- Obese (Class I): BMI 30.0–34.9 — approximately 13st 12lbs to 15st 5lbs (88–98kg) for a 5ft 8in adult
- Obese (Class II): BMI 35.0–39.9 — around 15st 5lbs to 17st 3lbs (98–109kg) for a 5ft 8in adult
- Severely obese (Class III): BMI 40.0 and above — 17st 3lbs (109kg) and over for a 5ft 8in adult
Your healthy weight range depends on your individual height — use our weight converter to find your exact stone equivalent, then calculate your personal BMI to see which category applies to you.
Clinically BackedWeight Loss
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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 Other Measures Matter
While a BMI chart in stone is useful for screening, it has important limitations. BMI cannot distinguish between muscle and fat — athletes or people with high muscle mass may have a high BMI but low body fat. It also doesn't account for where fat is stored; waist circumference is equally important for health risk assessment.
The NHS recommends looking at waist measurement alongside BMI. For men, a waist over 94cm (37in) indicates increased health risk; over 102cm (40in) is high risk. For women, the thresholds are 80cm (31.5in) and 88cm (34.5in) respectively. If you're concerned about your health, speak to your GP — they can assess your individual risk based on BMI, waist measurement, family history, and other health factors.
- 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 the healthy BMI range according to NHS guidelines?
The NHS healthy BMI range for adults is 18.5 to 24.9. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the lower threshold is 18.5 to 22.9, as these groups have higher health risks at the same BMI level. Your GP can advise on your personal healthy range.
How do I convert my weight from kg to stone to check the BMI chart?
Divide your weight in kg by 6.35 to get stone. For example, 70kg ÷ 6.35 = 11 stone. You can also use our free weight converter above to switch between kg, stone, and pounds instantly.
Why doesn't my BMI chart show my actual weight category?
BMI varies by height — two people weighing the same can have very different BMIs. The BMI formula is weight (kg) ÷ height (m)². Use our free BMI calculator above to enter your height and weight for your accurate personal BMI.
Can I be healthy with a BMI above the healthy range?
Some people with higher BMI have good health markers, especially if they have high muscle mass. However, excess weight does increase risk of type 2 diabetes, heart disease, and other conditions. Your GP can assess your individual health profile and recommend next steps if needed.
What's the difference between the NHS BMI chart and other countries' BMI ranges?
The NHS BMI chart is specifically designed for UK adults using UK research. Some countries use different thresholds. The NHS chart also has adjusted categories for people of South Asian and other backgrounds, reflecting their specific health risks at different BMI levels.
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.