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 55kg in Stone and What's Your BMI?
55 kilograms is equivalent to 8 stone 8.6 pounds in UK measurements. However, whether this weight is healthy for you depends on your height — the same weight can give a very different BMI depending on how tall you are. Use our free BMI calculator above to check your personal BMI instantly, then compare it against NHS guidelines. This guide shows what BMI 55kg gives at different heights and helps you understand where your weight falls on the NHS health scale.
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 BMI Does 55kg Give at Different Heights?
To convert kilograms to stone, we divide by 6.35. So 55kg equals 8 stone 8.6 pounds. But BMI also depends on height — the same weight looks very different on someone who is 5 feet tall versus 6 feet tall. Here's what BMI 55kg gives at common UK heights:
- At 150cm (4ft 11in): BMI 24.4 — healthy weight (NHS green zone)
- At 160cm (5ft 3in): BMI 21.5 — healthy weight
- At 165cm (5ft 5in): BMI 20.2 — healthy weight
- At 170cm (5ft 7in): BMI 19.0 — healthy weight
- At 175cm (5ft 9in): BMI 17.9 — healthy weight
- At 180cm (5ft 11in): BMI 16.9 — underweight (below NHS healthy range)
As you can see, at most typical adult heights, 55kg falls comfortably in the healthy weight range. Use the weight converter on this page to check other weight measurements.
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.
NHS BMI Categories and Why They Matter
The NHS defines a healthy BMI as 18.5 to 24.9 for most UK adults. A BMI below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese. However, BMI is only a screening tool — it doesn't account for muscle mass, bone density, or where fat is stored. Someone who is very muscular may have a high BMI but be perfectly healthy. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds because these groups face higher health risks at the same BMI. If you're unsure whether your weight is healthy for you, your GP can give personalised advice based on your overall health picture.
- 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.
Is 55kg a healthy weight?
For most adult heights, yes — 55kg typically falls in the healthy BMI range (18.5–24.9). However, it depends on your height. Use our BMI calculator above to check your personal BMI. If you're very tall, 55kg might be underweight; if you're shorter, it may be at the upper end of healthy. Your GP can advise on what's right for you.
How do I convert 55kg to stone and pounds?
To convert kilograms to stone, divide by 6.35029. So 55kg ÷ 6.35 = 8.67 stone. This equals 8 stone and 8.6 pounds. Use the weight converter on this page to convert between kg, stone, and pounds instantly.
What is the healthy weight range at my height?
The healthy BMI range is 18.5–24.9. To find your healthy weight range, multiply your height in metres squared by 18.5 (lower bound) and 24.9 (upper bound). For example, at 1.70m tall, the healthy range is 53.4kg to 71.9kg (8st 6lbs to 11st 4lbs).
Does BMI account for muscle mass?
No — BMI is calculated from height and weight only, so it cannot distinguish between fat and muscle. Someone who is athletic or very muscular may have a high BMI but be in excellent health. For a fuller picture, your GP can discuss waist circumference and overall health markers alongside BMI.
Are BMI thresholds the same for everyone?
No. The NHS recommends lower BMI thresholds for people of South Asian, Chinese, Black African, or Black Caribbean heritage because these groups have higher risk of type 2 diabetes and heart disease at lower BMI levels. If you're from one of these backgrounds, discuss your personal healthy weight range with your GP.
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.