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
What Is 15.9 Stone in Pounds — And What's Your BMI?
15.9 stone is equivalent to 222.6 pounds. However, your BMI depends entirely on your height — the same weight can give a healthy BMI for a tall person or an overweight BMI for someone shorter. We've calculated your BMI at six common heights below to help you understand what this weight means for your health using NHS guidelines. Use our free BMI calculator above to find your exact BMI instantly if your height isn't listed, or use the weight converter to check the kilogram equivalent (101.1 kg).
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
What Is Your BMI at 15.9 Stone?
15.9 stone (222.6 lbs / 101.1 kg) gives these BMI values at common heights:
- 5ft 2in (157 cm): BMI 41.6 — Severely obese (Class III)
- 5ft 5in (165 cm): BMI 37.0 — Obese (Class II)
- 5ft 8in (173 cm): BMI 33.1 — Obese (Class I)
- 5ft 10in (178 cm): BMI 30.2 — Obese (Class I)
- 6ft 0in (183 cm): BMI 27.6 — Overweight
- 6ft 2in (188 cm): BMI 25.4 — Healthy weight
These calculations use the NHS standard BMI categories for UK adults. Your GP can discuss your individual health needs regardless of your BMI category.
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.
Understanding BMI Categories and Limitations
The NHS BMI categories range from underweight (below 18.5) through healthy weight (18.5–24.9), overweight (25–29.9), and obese (30 and above). However, BMI has important limitations: it doesn't distinguish between muscle and fat, so athletes may have a high BMI despite low body fat. It also doesn't account for where fat is stored — waist measurement matters too. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds, as these groups face higher health risks at equivalent weights. Use our weight converter to check your weight in different units, and speak with your GP about what a healthy weight range means for you personally.
- 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 convert 15.9 stone to kilograms?
15.9 stone equals 101.1 kg. To convert any weight in stone to kg, multiply the stone figure by 6.35029. You can use our free weight converter on this page to switch between stone, pounds, and kilograms instantly.
Is 15.9 stone overweight or obese?
That depends entirely on your height. At 5ft 8in, 15.9 stone gives a BMI of 33.1 (Obese Class I). At 6ft 2in, it's a BMI of 25.4 (Healthy weight). Your height is the key factor. Use the BMI calculator above to find your personal BMI.
What is the healthy weight range at my height?
The healthy weight range varies by height. For example, at 5ft 8in, healthy weight is 8st 10lbs to 11st 10lbs (55–74 kg). Your GP or our free BMI calculator can tell you the healthy range for your specific height and health profile.
Do I need to see my GP about my weight?
If you have concerns about your weight or health, speaking with your GP is always sensible. They can assess your individual circumstances, consider other health factors beyond BMI, and discuss any support or treatment options that might help you.
What does BMI not tell me about my health?
BMI doesn't show whether weight is from muscle or fat, doesn't account for where fat is stored (waist measurement matters), and varies in accuracy for older adults, athletes, and during pregnancy. It's a useful screening tool but only part of the picture — your GP can give you fuller health context. ```
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.