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
Ask Imperial — Understanding UK Weight Measurements
Imperial measurements remain deeply embedded in UK culture, even though the UK officially adopted the metric system decades ago. Most British adults still think about their body weight in stone and pounds rather than kilograms, making imperial measurements essential for understanding weight, health, and fitness in a UK context. This guide explains imperial weight units, how they relate to NHS health guidance, and how to convert between imperial and metric measurements for your personal health planning.
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 Imperial Still Matters in UK Health and Fitness
Despite metric being the official UK standard, imperial measurements remain the everyday language for British adults discussing weight. The NHS recognises this cultural preference and provides guidance in both metric and imperial formats. Stone and pounds are the traditional imperial units used in the UK — one stone equals exactly 14 pounds, and one pound equals 0.454 kilograms.
- Most UK adults naturally discuss their weight in stone and pounds (e.g., "I weigh 12 stone 8 pounds")
- UK clothes sizing, diet programmes, and fitness apps frequently use stone
- NHS guidelines provide healthy weight ranges in both kg and stone for British adults
- Understanding your weight in imperial helps you relate to UK-specific health resources and conversations with your GP
Using our free weight converter above, you can instantly switch between imperial and metric measurements. This is particularly useful when reading health information that may be presented in either 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 Imperial to Metric — Quick Reference
Converting between imperial and metric is straightforward once you know the key values. One kilogram equals 2.20462 pounds, and one stone equals 6.35029 kilograms. For example, 70 kilograms converts to approximately 11 stone (or 154 pounds), while 12 stone converts to 76.2 kilograms. The weight converter tool on this page handles these calculations instantly, but knowing the rough conversions helps you understand health guidance in either system. NHS healthy weight ranges for UK adults fall between BMI 18.5 and 24.9, which translates to roughly 50–75 kg for a person who is 1.73 metres tall — or approximately 7st 12lbs to 11st 11lbs in imperial.
- 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.
Why do UK adults still use stone and pounds instead of kilograms?
Stone and pounds are deeply embedded in British culture and everyday conversation. Most UK adults learned to think about weight in imperial units growing up, and this preference has persisted even though the UK adopted metric officially. The NHS acknowledges this cultural reality by providing weight guidance in both systems, making imperial measurements essential for UK health discussions.
What is the exact conversion from stone to kilograms?
One stone equals exactly 6.35029 kilograms. To convert stone to kilograms, multiply the stone weight by 6.35029. For example, 10 stone × 6.35029 = 63.5 kg. You can use our free weight converter above to do this instantly without a UK pharmacy calculation.
How do imperial measurements relate to NHS healthy weight guidance?
The NHS provides healthy weight ranges in both metric and imperial formats. A healthy BMI of 18.5–24.9 translates to specific weight ranges depending on your height. Our free BMI calculator above can show your healthy weight range in both stone and kilograms, helping you understand NHS guidance in whichever system you prefer.
Is it better to track weight loss in stone or kilograms?
Either system works — choose whichever feels most natural to you. Many UK adults prefer stone because it's culturally familiar, but kilograms allow you to track smaller changes more precisely (you can measure to 0.1 kg rather than just pounds). Our free progress tracker lets you log weight in either system and switch between them as you progress.
Should I discuss weight in imperial or metric with my GP?
Your GP understands both systems and will use whichever you prefer. Most NHS systems record weight in kilograms, but your GP is accustomed to discussing weight with patients in stone and pounds. Bring your weight in whichever format feels comfortable — your GP will convert if needed for clinical records.
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.