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 Converter for UK Adults — kg, Stone & Pounds
A weight converter helps you switch between kilograms, stone, and pounds — the three measurement systems used across UK health, fitness, and everyday life. Whether your GP gives you a health target in kilograms, your scales show pounds, or you're comparing weights in stone, our free weight converter makes it simple. Understanding your weight in all three units helps you track progress more effectively and engage with NHS health guidance, which uses kilograms for clinical purposes whilst many UK adults naturally think in stone and pounds.
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.
Why Weight Conversion Matters for UK Health
In the UK, weight measurement can feel confusing because we use multiple systems simultaneously. The NHS uses kilograms for clinical measurements and health guidance, yet most UK adults still prefer stone and pounds for personal weight tracking. Your GP might refer to targets in kg, your bathroom scales might show pounds, and your friends probably talk about weight in stone. Being able to convert between these units instantly helps you understand your health in whichever measurement feels most familiar.
- Kilograms (kg): Used by the NHS, healthcare professionals, and international health standards
- Stone and pounds (st/lbs): Traditional UK system still widely used in everyday life
- Pounds only (lbs): Used on some scales and in American health contexts
Our free weight converter on this page lets you switch between all three instantly, removing confusion and helping you engage fully with UK health guidance. Combined with our BMI calculator, a weight converter becomes even more powerful — you can check how different weights affect your health status.
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 in UK Health Contexts
When your GP discusses your weight, they'll almost certainly use kilograms and reference NHS health thresholds. A healthy weight according to NHS guidelines sits within a BMI of 18.5 to 24.9 — but what does that mean in stone? Using a weight converter alongside our free BMI calculator lets you see exactly where you stand and what a healthy weight range looks like in your preferred measurement. For example, a 5ft 8in adult (173cm) with a healthy BMI would weigh between approximately 55kg (8st 10lbs) and 75kg (11st 10lbs). Whether you're monitoring your own health, supporting someone else, or simply curious about how these measurements compare, a reliable converter removes the arithmetic and helps you focus on what matters — your wellbeing.
- 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 measurements — 1 stone equals exactly 14 pounds. Kilograms are the metric system used by the NHS and most of the world. To convert: 1 kg = 0.157 stone, or 1 stone = 6.35 kg. Our free weight converter handles all the maths instantly.
Why does the NHS use kilograms if we use stone in the UK?
The NHS uses kilograms to align with international medical standards and clinical research. However, NHS patient guidance recognises that many UK adults think in stone, so health information is often presented in both units. Using a weight converter helps bridge this gap.
How do I calculate my healthy weight in stone?
Use our free BMI calculator to find your healthy weight range — it shows results in both kilograms and stone automatically. Alternatively, a healthy BMI for most adults is 18.5 to 24.9. Multiply your height in metres by itself, then multiply by 18.5 and 24.9 to get your healthy weight range in kg, then convert to stone.
Can I use a weight converter to check if I'm overweight?
A weight converter alone won't tell you if you're overweight — you need context about your height. That's why our free BMI calculator is more useful. It combines your weight (in any unit) with your height to show whether you're in a healthy range according to NHS guidelines.
Is converting my weight between units useful for weight loss tracking?
Yes. If you're tracking weight loss, being able to convert between kg and stone helps you see progress in whichever unit feels most motivating. Some people find pounds more encouraging (smaller numbers) whilst others prefer kilograms. Use our free progress tracker alongside the weight converter for complete tracking flexibility. ```
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.