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 Kilos in Stone and What's Your BMI?
57 kilograms equals approximately 8 stone 13.7 pounds in UK measurements. However, your BMI at this weight depends entirely on your height — the same weight can be healthy for one person and overweight for another. To convert kilograms to stone accurately, divide 57 by 6.35, which gives you 8 stone 13.7 lbs. Use our free BMI calculator above to find your exact BMI instantly by entering your height and weight.
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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.
57kg BMI at Different Heights
Your BMI at 57kg varies significantly depending on how tall you are. Here are example BMI values at common UK heights:
- 5ft 2in (158cm): BMI 21.4 — healthy weight (NHS category)
- 5ft 4in (163cm): BMI 20.0 — healthy weight
- 5ft 6in (168cm): BMI 18.6 — healthy weight
- 5ft 8in (173cm): BMI 17.4 — healthy weight
- 5ft 10in (178cm): BMI 16.3 — underweight (below healthy range)
- 6ft 0in (183cm): BMI 15.2 — underweight
At 57kg, most adults of average to taller heights will fall into the healthy weight range. Shorter adults may find themselves at the higher end of healthy or just above. For personalised advice about whether this weight is healthy for you, consult your GP.
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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 BMI Categories and Limitations
According to NHS guidelines, healthy BMI ranges are:
- Below 18.5 — underweight
- 18.5–24.9 — healthy weight
- 25.0–29.9 — overweight
- 30.0 and above — obese
BMI is a useful screening tool but has important limitations. It does not distinguish between muscle and fat, so athletes may have a high BMI despite low body fat. BMI also does not account for where fat is stored — waist circumference matters too. For South Asian, Chinese, Black African, or Black Caribbean adults, slightly lower BMI thresholds are recommended. Use our free weight converter to check your weight in different units, and speak to your GP about what your BMI means for your overall health.
- 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 57kg in stone and pounds?
57 kilograms equals 8 stone and 13.7 pounds (or approximately 8 stone 14 lbs when rounded). To calculate this yourself, divide 57 by 6.35029 to get stone, then multiply the decimal by 14 to get the remaining pounds.
Is 57kg a healthy weight?
Whether 57kg is healthy depends on your height and individual health factors. At 57kg, someone who is 5ft 4in tall would have a BMI of 20, which is healthy according to NHS guidelines. Taller adults may be underweight at this weight. Your GP can advise whether this weight is appropriate for you personally.
How do I calculate my BMI at 57kg?
BMI is calculated as weight in kg divided by height in metres squared. For 57kg, divide 57 by your height (in metres) squared. For example, at 1.63m tall, 57 ÷ (1.63 × 1.63) = BMI 21.4. Use our free BMI calculator above to calculate yours instantly.
What is the healthy weight range for my height?
The healthy BMI range is 18.5–24.9 according to NHS guidelines. To find your healthy weight range, multiply your height (in metres) squared by both 18.5 and 24.9. For someone 1.70m tall, the healthy range is approximately 53–72kg (8st 5lbs–11st 4lbs).
Does BMI account for muscle mass?
No — BMI does not distinguish between muscle and fat. Athletes may have a high BMI despite low body fat. BMI is a screening tool only. Your GP may also consider waist circumference, fitness level, and medical history to get a fuller picture of your health.
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.