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
NHS Weight Conversion: UK Health Standards Explained
The NHS uses kilograms for clinical measurements, but UK adults typically think in stone and pounds. Understanding how to convert between these measurements is essential for interpreting your NHS health advice and managing your weight effectively. Whether you're reviewing NHS guidance, attending a health appointment, or using online health tools, knowing how weight conversions work helps you stay informed about your health status and progress.
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.
How NHS Weight Conversion Works in the UK
The NHS uses kilograms (kg) as the standard unit for clinical weight measurements, though patient communication often includes stone and pounds. The standard conversion is straightforward: 1 kilogram equals 0.157473 stone, or conversely, 1 stone equals 6.35029 kilograms. For practical purposes, dividing your weight in kg by 6.35 gives you stone quickly.
When interpreting NHS BMI guidance, the calculation uses kilograms and metres, but you can use our free BMI calculator above to enter your weight in any unit and see your gradual improvement. The NHS categorises healthy weight as a BMI between 18.5 and 24.9, though for adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds starting at 18.5 to 22.9.
Our free weight converter helps you instantly switch between kg, stone, and pounds—essential for tracking health metrics across different sources.
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.
Using Your NHS Weight Measurements at Home
When your GP or NHS health service records your weight in kilograms, understanding the stone equivalent helps you track progress personally. Many UK diet programmes, fitness apps, and personal scales use stone and pounds, making conversion essential for consistency. The key is using the same unit throughout your health journey to avoid confusion and accurately monitor changes.
NHS health guidance on weight management recommends a sustainable loss of 0.5 to 1 kg per week (roughly 1 to 2 pounds). If you're exploring NHS weight management options or specialist services, your prescriber will discuss measurements in both metric and imperial units. Use our free weight converter on this page whenever you need to switch between units for clarity and confidence in your health decisions.
- 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 does the NHS use kilograms but UK patients prefer stone?
The NHS adopted kilograms for clinical consistency with international medical standards and BMI calculations. However, UK culture traditionally uses stone and pounds for personal weight. Both are correct—it's simply about context. Your GP's records will use kg, but your personal understanding often works better in stone.
How do I convert my NHS weight measurement to stone?
Divide your weight in kilograms by 6.35029. For example, 70 kg divided by 6.35 equals 11 stone and 0.1 pounds. Use our free weight converter above for instant, accurate conversions without a UK pharmacy calculation.
Does NHS BMI calculation differ from standard BMI?
No. NHS BMI uses the same formula: weight (kg) divided by height (metres) squared. The NHS categories are standard (18.5–24.9 = healthy weight), though lower thresholds apply to certain ethnic groups. Try our free BMI calculator to see your personal BMI and category instantly.
Can I use stone measurements for NHS appointments?
You can mention your weight in stone, but your GP's system records in kilograms. Always ask your healthcare provider to confirm the conversion is correct. Having both measurements ensures clarity and prevents any medical record errors.
How often should I convert my weight for health tracking?
Convert consistently using one unit for personal tracking, then convert to the other only when comparing with NHS records or discussing with your GP. Consistency prevents confusion. Our weight converter makes switching between units quick whenever you need it.
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.