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 57 Kg In Stone — And What's Your BMI?
57 kilograms converts to approximately 8 stone 13 pounds in UK measurements. However, whether this weight is healthy for you depends entirely on your height — the same weight gives very different BMI results at different heights. Your BMI tells you whether 57kg falls into the healthy, overweight, or obese category according to NHS guidelines. Use our free BMI calculator above to check your personal BMI instantly, or read on to see example BMI values at different heights.
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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.
57 Kg BMI At Different Heights
At 57 kg, your BMI depends on your height. Here's what your BMI would be at common UK heights:
- 5ft 2in (157cm) — BMI 23.1 (healthy weight)
- 5ft 4in (163cm) — BMI 21.3 (healthy weight)
- 5ft 6in (168cm) — BMI 19.9 (healthy weight)
- 5ft 8in (173cm) — BMI 18.5 (healthy weight, at lower threshold)
- 5ft 10in (178cm) — BMI 17.4 (underweight)
- 6ft (183cm) — BMI 16.1 (underweight)
As you can see, 57kg is healthy for shorter adults but falls into the underweight category for taller people. To convert your weight between kilograms and stone using different measurements, try our free weight converter on this page. Always check with your GP if you're concerned about your weight or BMI.
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.
UK Guidance and Next Steps
NHS BMI Categories (Standard Thresholds)
- Below 18.5 — Underweight
- 18.5 to 24.9 — Healthy weight
- 25.0 to 29.9 — Overweight
- 30.0 and above — Obese
If you're of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds: healthy weight is 18.5 to 22.9, and overweight starts at 23.0. BMI is a useful screening tool, but it has limitations — it doesn't account for muscle mass or where fat is stored. Your waist measurement and overall health matter too. Your GP can give you personalised health advice based on your individual 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 57kg to stone and pounds?
Divide 57 by 6.35 to get stone: 57 ÷ 6.35 = 8.98 stone, which is approximately 8 stone 13 pounds. Use our free weight converter on this page for instant conversions between kg, stone, and pounds — it's much quicker than doing the maths yourself.
Is 57kg a healthy weight?
Whether 57kg is healthy depends on your height. At 5ft 4in it's healthy (BMI 21.3), but at 6ft it's underweight (BMI 16.1). Use our free BMI calculator above to check your personal BMI and NHS health category. Always speak to your GP if you have concerns about your weight.
What does BMI mean and why does it matter?
BMI (body mass index) is a screening tool that shows whether your weight is in a healthy range for your height according to NHS guidelines. It helps identify health risks, though it has limitations because it doesn't distinguish between muscle and fat. Your GP uses BMI alongside other measurements to assess your health.
Is BMI accurate for everyone?
BMI is useful for most adults, but it has limitations. It doesn't account for muscle mass (athletes may have high BMI but low body fat), bone density, or where fat is stored. For South Asian and Black heritage adults, lower BMI thresholds apply due to higher cardiovascular risk. Your GP can give you personalised advice about what your BMI means for you.
Can I lose weight healthily?
The NHS recommends losing 0.5 to 1kg per week through a calorie deficit and increased physical activity. If you're interested in structured support, ask your GP about tier 1 weight management services, NHS weight loss programmes, or referral to specialist services. Try our progress tracker to log your weight loss journey.
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.