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
Weight in UK Conversion — Your Complete Guide
Understanding how to convert weight between kilograms, stone, and pounds is essential for UK health contexts. Whether you're reading NHS health advice, tracking your weight, or discussing health with your GP, knowing how to convert between these measurements helps you engage with health information confidently. This guide explains weight conversion in UK context and shows you how to use our free weight converter to switch between units 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.
UK Weight Measurements and NHS Health Guidance
In the UK, weight is measured using three different units depending on context. Stone and pounds remain the most common way UK adults discuss personal weight, despite the NHS using kilograms for clinical measurements. Understanding all three units helps you navigate UK health information effectively.
- Stone (st): 1 stone = 6.35029 kg exactly. Still the traditional UK unit for body weight.
- Pounds (lbs): 1 pound = 0.453592 kg. Often combined with stone (e.g., 12 stone 7 pounds).
- Kilograms (kg): The metric unit used in NHS clinical settings, medical research, and international comparisons.
The NHS and NICE guidelines reference weight in kilograms for clinical thresholds like BMI categories and healthy weight ranges, but patient discussions often use stone. Use our free weight converter above to switch between any of these units instantly—just enter your weight and select your preferred output format.
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.
Converting Weight for UK Health Decisions
Accurate weight conversion matters when you're checking your health status against NHS guidance or tracking weight loss progress. For example, if your GP tells you your healthy weight range should be between 65–85 kg, converting to stone (10 stone 3 lbs to 13 stone 5 lbs) helps you understand what that means in familiar UK terms.
The BMI calculator on this page automatically handles conversions and shows your BMI category against NHS thresholds. If you're considering weight management options like GLP-1 medications (Mounjaro or Wegovy), eligibility is based on BMI thresholds—our GLP-1 weight loss calculator can help you understand potential outcomes. Always consult your GP about your personal weight and health status, as individual circumstances vary significantly.
- 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's the difference between stone, pounds, and kilograms?
Stone and pounds are traditional UK units. One stone equals 14 pounds or 6.35 kg. Kilograms are the metric unit used in NHS clinical settings. The UK uniquely uses stone for personal weight while NHS uses kg for medical thresholds—our free converter helps you switch between all three instantly.
Why does the NHS use kilograms if UK people use stone?
The NHS adopted the metric system (kilograms) for clinical consistency, medical research, and international comparison. However, UK patients and GPs still commonly discuss weight in stone in conversation. Both units are equally valid—choose whichever feels most natural to you.
How do I convert my weight to stone for my GP appointment?
Use our free weight converter above—just enter your weight in any unit and select stone as your output. For example, 80 kg converts to 12 stone 8 pounds. Your GP is familiar with both units, so you can use whichever you prefer when discussing your weight and health.
Is my weight healthy according to UK guidelines?
The NHS defines healthy weight using BMI categories: 18.5 to 24.9 for most adults. Use our free BMI calculator on this page to check your personal BMI instantly. For South Asian, Chinese, Black African, or Black Caribbean adults, the NHS recommends lower thresholds (18.5 to 22.9). Always ask your GP for personalised advice about your weight.
Where can I find UK-specific weight management guidance?
The NHS and NICE provide official weight management guidance at nhs.uk. Your GP can refer you to local weight management services, or you can explore NHS resources directly. Our free BMI and GLP-1 weight loss calculators on this page provide NHS-aligned information to support your understanding of weight health in UK context.
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.