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
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What Is 57.9 Kilos in Pounds and BMI?
57.9 kilos converts to approximately 127.6 pounds or 9 stone 1.6 lbs in UK measurements. However, your BMI — which is the key health indicator for this weight — depends entirely on your height. This guide shows you what 57.9kg means for your health at different heights, using NHS BMI categories to help you understand where you fall on the healthy weight spectrum.
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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.
BMI at 57.9kg for Different Heights
At 57.9 kg (127.6 lbs), your BMI varies significantly depending on your height. Here's what your BMI would be at common adult heights:
- 160 cm (5ft 3in): BMI 22.6 — Healthy weight
- 165 cm (5ft 5in): BMI 21.2 — Healthy weight
- 170 cm (5ft 7in): BMI 20.0 — Healthy weight
- 175 cm (5ft 9in): BMI 18.9 — Healthy weight
- 180 cm (5ft 11in): BMI 17.8 — Underweight
- 185 cm (6ft 1in): BMI 16.9 — Underweight
Use our free BMI calculator above to enter your exact height and see your personal BMI instantly. At 57.9kg, most adults fall comfortably within the healthy weight range of 18.5–24.9, though this depends on your individual height.
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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 BMI Categories and Limitations
The NHS defines healthy BMI as 18.5–24.9 for most adults. At 57.9kg, you're likely in a healthy range if you're of average height or taller. However, BMI has important limitations — it doesn't distinguish between muscle and fat, so athletes with high muscle mass may have a higher BMI without excess body fat. For South Asian, Chinese, Black African, or Black Caribbean adults, the NHS recommends lower BMI thresholds due to higher health risks at standard BMI levels. Weight is just one aspect of health; your GP can provide personalised guidance based on your complete health picture, including waist circumference and fitness level.
- 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 57.9 kilos to pounds and stone?
57.9kg equals 127.6 pounds (lbs) or 9 stone 1.6 lbs in UK measurements. You can use our free weight converter above to instantly convert between kg, stone, and pounds for any weight value.
Is 57.9kg a healthy weight?
At 57.9kg, whether your weight is healthy depends on your height and overall health. Most adults at this weight fall within the NHS healthy BMI range of 18.5–24.9. Use our BMI calculator above to check your personal BMI — it only takes seconds.
What is the healthy weight range for someone 170cm tall weighing 57.9kg?
For 170cm (5ft 7in), the healthy BMI range (18.5–24.9) corresponds to weights of approximately 53.5–71.5kg. At 57.9kg, this height gives a BMI of 20.0, which is comfortably in the healthy range.
Why does BMI change with height but not weight?
BMI is calculated as weight divided by height squared. The same weight produces different BMI values at different heights because taller individuals are proportionally larger. A weight that's healthy for someone 180cm tall may be underweight for someone 160cm tall.
Should I be concerned if my BMI is at the edge of the healthy range?
No — the healthy BMI range is broad (18.5–24.9) to account for natural variation in body composition. If your BMI is within this range, you're at lower health risk. However, other factors like waist circumference, fitness, and blood pressure also matter. Your GP can offer personalised health advice.
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.