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 55 kg in stone?
55 kilograms is equal to 8 stone and 8.6 pounds (or 8st 8.6lbs) in UK measurements. This straightforward conversion uses the standard formula of dividing kilograms by 6.35029. Whether you're checking your weight against NHS health guidance, understanding a medical measurement, or simply converting between metric and imperial units, knowing your weight in stone helps you contextualise your health within UK health information systems. Our weight converter tool above makes it easy to switch between kg, stone, and pounds instantly.
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.
Where does 55kg sit in NHS health guidance?
At 55kg, your health context depends entirely on your height. According to NHS guidance, a healthy BMI falls between 18.5 and 24.9. For example, an adult who is 163cm tall (5ft 4in) with a weight of 55kg would have a BMI of approximately 20.7 — firmly in the healthy weight range. However, if you are taller — say 180cm (5ft 11in) — the same 55kg weight would give a BMI of around 17.0, which is below the healthy range and classified as underweight.
Use our free BMI calculator above to check your personal BMI instantly by entering your height and current weight. This gives you a clearer picture of how 55kg relates to NHS health thresholds for your individual height. Remember that BMI is a useful screening tool, but it does not account for muscle mass or where fat is stored — your GP can provide personalised advice about what your weight means for your specific health.
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 resources and tools for weight management
If you're tracking your weight or considering weight management, several free UK health resources are available to support you. The NHS Healthy Weight Calculator (available on the NHS Every Mind Matters website) helps you understand your personal healthy weight range based on your height. Our free weight converter lets you switch seamlessly between kg, stone, and pounds — essential when comparing your weight across different health services or personal health apps.
For ongoing tracking, our progress tracker tool lets you log weight changes over time and spot trends. If you have concerns about your weight or health, always speak to your GP, who can assess your individual circumstances and discuss any support or interventions that may be appropriate for you.
- 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 the exact conversion from 55kg to stone?
55kg equals 8 stone and 8.6 pounds (8st 8.6lbs). The conversion formula is weight in kg ÷ 6.35029 = stone. For 55kg: 55 ÷ 6.35029 = 8.665 stone, which is 8 stone plus 0.665 × 14 pounds = 8st 8.6lbs. Our weight converter above calculates this instantly.
Is 55kg a healthy weight?
Whether 55kg is healthy depends on your height. At 163cm (5ft 4in), a BMI of approximately 20.7 is healthy. At 180cm (5ft 11in), the same weight gives a BMI of 17.0 (underweight). Use our BMI calculator above to check your personal BMI and see where you sit within NHS health guidelines for your height.
What is the healthy weight range for someone at a specific height?
The NHS healthy weight range (BMI 18.5–24.9) varies by height. For example, at 168cm (5ft 6in), healthy weight is approximately 52–70kg (8st 2lbs to 11st 0lbs). Our free BMI calculator shows your personalised healthy weight range instantly when you enter your height and current weight.
How does 55kg compare to average UK adult weight?
According to ONS data, the average UK adult woman weighs approximately 71.6kg (11st 3lbs) and the average UK adult man weighs approximately 85.7kg (13st 7lbs). At 55kg, this weight is below the current UK average, though individual healthy weight varies significantly based on height, body composition, and genetics.
Should I see my GP about my weight at 55kg?
If you have concerns about your health or weight, or if you're struggling with energy levels, it's always worth speaking to your GP. They can assess your individual circumstances, check your BMI in context of your height, and discuss whether any support or interventions are appropriate for you.
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.