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
Free tracker included with every download this week
Understanding Stone Measurement in the UK
Stone is the standard unit for measuring body weight across the UK, used in NHS clinics, GP surgeries, and everyday conversation. Unlike most of Europe and the rest of the world, which use kilograms exclusively, the UK maintains stone (often written as "st") as the primary weight measurement for adults. One stone equals exactly 14 pounds or approximately 6.35 kilograms. Understanding how stone works is essential for interpreting your health information, tracking weight management, and communicating with healthcare professionals about your weight health.
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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.
How Stone Works in UK Health Measurement
Stone is the official UK unit for body weight in NHS health guidance and clinical practice. One stone = 14 pounds exactly, and one stone = 6.35 kg. When NHS professionals record your weight, they typically convert to kilograms for medical records, but they will communicate your weight in stone and pounds when discussing it with you. For example, a weight of 70 kg converts to 11 stone and 0.1 lbs — the NHS standard format. This dual system reflects UK healthcare integration: clinical systems use metric (kg), but patients understand stone. You'll see stone listed on weight management NHS guidance, prescription weight loss information, and your GP's health advice. Our free weight converter above makes switching between stone, pounds, and kilograms instant — simply enter your weight and see all three units. Understanding your weight in stone also helps with tracking progress using our free progress tracker, which supports both metric and imperial units, making UK weight management intuitive and personalised.
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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.
Stone and NHS Health Guidance
The NHS provides healthy weight guidance using BMI, which is calculated from weight in kilograms and height in metres. However, NHS professionals translate BMI results back into stone and pounds for UK patients. A healthy BMI range (18.5–24.9) corresponds to a specific stone and pound range depending on your height — use our free BMI calculator above to find your personal healthy weight range in stone. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds, starting at BMI 23 (not 25). Understanding stone measurement helps you communicate with your GP about weight-related health conditions, interpret weight loss medication guidance (including GLP-1 weight loss injections, which are prescribed in the UK), and set realistic weight management goals aligned with NHS recommendations.
- 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 many pounds are in one stone?
One stone equals exactly 14 pounds. This is the standard UK conversion. So if you weigh 12 stone, that's 168 pounds (12 × 14). To convert stone and pounds to kilograms, multiply stone by 6.35 and pounds by 0.454, then add them together.
What is the stone measurement in kilograms?
One stone = 6.35029 kilograms. The NHS uses kilograms for clinical records, but stone for patient communication. To convert stone to kg, divide your weight in kilograms by 6.35. Most UK adults think in stone but their GP's records are in kg.
How do I convert my weight from stone to kg using a formula?
Multiply your stone by 6.35029, then add (pounds × 0.453592). For example: 11 stone 0 pounds = (11 × 6.35) + (0 × 0.454) = 69.85 kg. Our free weight converter above does this instantly — just enter your stone and pounds.
What is the healthy weight range in stone according to the NHS?
The healthy weight range depends on your height. Use our free BMI calculator to find your personal healthy weight range in stone and pounds. For a 5ft 8in person, the healthy range is roughly 8st 10lbs to 11st 10lbs. Your GP can also advise you based on your individual health.
Is stone measurement used in NHS weight management guidance?
Yes. The NHS uses stone and pounds when discussing weight with UK patients, though clinical records are in kilograms. All NHS healthy weight guidance, weight loss medication information, and GP advice about your weight will reference stone. It's the standard across UK health services and 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.