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 and Feet — NHS Health Guide
Understanding your BMI using UK measurements is straightforward when you use the right reference chart. The NHS BMI formula calculates your body mass index using your weight in kilograms and height in metres, but we've converted this into stone, feet, and inches so it's easy to understand. This guide shows you what the NHS considers a healthy BMI range, how BMI categories work, and what your personal BMI means for your health. Use our free BMI calculator above to find your exact BMI instantly, or read on to understand the chart and NHS guidance.
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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 range divides adults into four main categories based on health risk. A healthy BMI falls between 18.5 and 24.9 — this is the range associated with the lowest health risks for most people. Being overweight means a BMI of 25.0 to 29.9, which increases certain health risks. Obese is BMI 30.0 to 34.9, and severely obese is 40.0 or above.
For context, a person who is 5ft 8in (173cm) tall with a BMI of 24.9 would weigh approximately 11st 10lbs (74.5kg). The same height at a BMI of 30.0 would be around 12st 8lbs (80kg). These thresholds are based on research showing increased risk of type 2 diabetes, heart disease, and other conditions above these BMI levels. The NHS also recognises that for people of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds apply — healthy weight starts at BMI 18.5 and overweight begins at 23.0 instead of 25.0.
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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 Support and When to Seek Help
If your BMI falls outside the healthy range, the NHS offers a structured weight management pathway. Your GP can assess your individual situation and may refer you to tier 1 services (digital tools and community programmes), tier 2 (primary care support), or tier 3 (specialist multidisciplinary weight management services). Tier 3 services can prescribe weight management medications like Mounjaro or Wegovy alongside lifestyle support.
The NHS recommends losing weight at a sustainable rate of 0.5 to 1kg per week through a combination of dietary changes and increased physical activity. Even losing 5–10% of your body weight can significantly improve blood sugar control, blood pressure, and reduce cardiovascular risk. Speak to your GP if you're concerned about your weight, especially if you have other health conditions like diabetes, high blood pressure, or sleep apnoea.
- 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 the NHS?
The NHS defines healthy BMI as between 18.5 and 24.9 for most adults. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the healthy range is 18.5 to 22.9 because these groups face higher health risks at higher BMI levels. Your GP can advise on what's healthy for you specifically.
How do I convert my weight in stone to BMI?
First convert your weight to kilograms (1 stone = 6.35kg). Then use the BMI formula: weight (kg) ÷ height (metres)². For example, 11 stone (70kg) at 1.73m tall gives a BMI of 23.4. Our free BMI calculator above does this instantly — just enter your measurements in stone and feet.
What does it mean if my BMI is between 25 and 29.9?
A BMI in this range is classified as overweight by the NHS. This suggests increased health risks compared to the healthy range, though individual risk varies based on other factors like fitness level, waist measurement, and medical history. Your GP can advise whether lifestyle changes or further assessment is recommended.
Are there limitations to using BMI?
Yes — BMI doesn't distinguish between muscle and fat, so athletes may have high BMI but low body fat. It also doesn't account for where fat is stored (abdominal fat is more risky) or age-related muscle loss. The NHS uses BMI alongside waist circumference and other health measures for a complete picture.
How can the NHS help me if my BMI is outside the healthy range?
Your GP can refer you to NHS weight management services, which range from digital support tools to specialist clinics. Tier 3 services can offer behavioural support, dietary guidance, and prescription medications. The NHS website has a free Weight Loss Plan, and your practice may offer community weight management programmes.
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.