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
27 Stone in Kilograms — What's Your BMI?
27 stone converts to 171.6 kg. However, your BMI depends on your height, not just your weight. At different heights, 171.6 kg produces different BMI values, ranging from the overweight category to severe obesity according to NHS guidelines. Understanding your personal BMI helps you assess health risk more accurately than weight alone. Use our free BMI calculator above to find your exact BMI based on your height and weight.
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.
27 Stone BMI at Different Heights
At 171.6 kg (27 stone), your BMI varies significantly depending on your height:
- 163 cm (5ft 4in): BMI 64.6 — Class III Obesity (Severely obese)
- 168 cm (5ft 6in): BMI 60.9 — Class III Obesity
- 173 cm (5ft 8in): BMI 57.4 — Class III Obesity
- 178 cm (5ft 10in): BMI 54.2 — Class III Obesity
- 183 cm (6ft 0in): BMI 51.2 — Obese Class II
- 188 cm (6ft 2in): BMI 48.5 — Obese Class II
All these heights fall into obesity categories according to NHS guidelines. A healthy BMI for any of these heights would be between 18.5 and 24.9. Calculate your precise BMI using the BMI calculator on this page — it accounts for your exact measurements.
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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.
Understanding NHS BMI Categories
The NHS categorises BMI as follows: 18.5–24.9 is healthy weight, 25–29.9 is overweight, 30–34.9 is Class I obesity, 35–39.9 is Class II obesity, and 40+ is Class III obesity. At 27 stone, you fall into one of the obesity categories depending on your height. It's important to note that BMI doesn't distinguish between muscle and fat — it's a screening tool, not a diagnostic measure. For a personalised health assessment and support with weight management, speak with your GP. They can discuss lifestyle changes, dietary support, or prescription weight loss options if appropriate for your circumstances.
- 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 27 stone to kilograms?
Multiply 27 by 6.35029. 27 stone = 171.6 kg. You can also use our free weight converter on this page to switch between stone, pounds, and kilograms instantly.
Is 27 stone considered obese?
At 27 stone (171.6 kg), BMI falls into obesity categories across all adult heights according to NHS guidelines. Specific classification depends on your height — it ranges from Class II to Class III obesity. Your GP can assess your individual health risks.
What's the healthy weight range for someone who weighs 27 stone?
A healthy weight depends on your height. For someone 5ft 8in, a healthy weight is approximately 55–74 kg (8st 10lbs to 11st 10lbs). Use our free BMI calculator to find the healthy weight range for your exact height.
Can I lose weight safely from 27 stone?
Yes. The NHS recommends losing 0.5–1 kg per week for sustainable results alongside a reduced-calorie diet and increased physical activity. Speak with your GP about support options, including referral to weight management services or potential prescription treatments if eligible.
What should I do if I'm concerned about my weight?
Start by speaking with your GP. They can assess your health, discuss lifestyle changes, refer you to NHS weight management services, or discuss prescription weight loss options like GLP-1 injections if appropriate. Track your progress using our free progress tracker.
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.