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 and Height Calculator for UK Adults
A weight and height calculator helps you understand your personal health metrics using UK measurements. Whether you're tracking your health journey or assessing your weight management goals, knowing your BMI and healthy weight range is the first step. MyWeightCheck provides free tools to convert your measurements, calculate your BMI, and access NHS-aligned health guidance — all designed specifically for UK adults using stone, pounds, and kilograms.
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 Weight and Height Measurements Work in UK Health
In the UK, health professionals use both metric (kilograms and centimetres) and imperial (stone and pounds) measurements, though the NHS typically records weight in kg for clinical purposes. Your BMI (body mass index) is calculated from your weight and height using the formula: weight in kg divided by height in metres squared.
- Height is usually recorded in centimetres or feet and inches
- Weight is commonly expressed in stone and pounds by UK adults, though NHS systems use kilograms
- A healthy BMI for most UK adults falls between 18.5 and 24.9
- For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds (18.5–22.9)
Your GP can provide personalised advice about what your measurements mean for your individual health, particularly if you have existing health conditions.
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 MyWeightCheck Tools for Your Health Assessment
MyWeightCheck provides a free BMI calculator that instantly computes your BMI from your weight and height in any UK measurement unit. You can also use our weight converter to switch between stone, pounds, and kilograms — helpful if you need to compare your measurements across different formats.
Beyond raw numbers, understanding your measurements in context matters. A healthy weight range depends on your individual circumstances, including age, muscle mass, and any weight-related health conditions. Our free tools work alongside NHS guidance to help you track your progress and make informed 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.
What's the difference between BMI calculated from weight and height?
BMI uses both your weight (in kg) and height (in metres) to estimate whether your weight falls within a healthy range for your height. Two people of the same weight can have very different BMIs if they are different heights. BMI is a screening tool — it doesn't measure body fat directly, so it has limitations, especially for very muscular individuals.
Can I use a weight and height calculator if I'm pregnant?
Standard BMI calculations are not accurate during pregnancy, as weight gain during pregnancy is expected and necessary. If you're pregnant, speak to your midwife or GP about appropriate weight management guidance during your pregnancy and after birth.
Why are there different BMI ranges for different ethnic groups?
Research shows that people from South Asian, Chinese, Black African, and Black Caribbean backgrounds have higher health risks at lower BMI levels compared to white European populations. The NHS therefore recommends lower BMI thresholds for these groups to better identify those at risk of weight-related conditions like type 2 diabetes.
Is BMI accurate for children and teenagers?
No — children's BMI is assessed differently using age and sex-specific growth charts (UK90 centile charts). Adult BMI categories don't apply to young people. If you're concerned about a child's weight, speak to your GP or health visitor for a proper assessment.
What should I do after calculating my BMI?
If your BMI falls outside the healthy range (18.5–24.9 for most adults), consider speaking to your GP. They can assess your individual circumstances, discuss any weight-related health conditions, and provide tailored guidance on nutrition, physical activity, or referral to specialist weight management services if appropriate.
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.