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
Calculate Correct Weight for Your UK Health
Calculating your correct weight isn't just about a number on the scales — it's about understanding what constitutes a healthy weight for you as an individual. In the UK, the NHS uses BMI (Body Mass Index) as the primary screening tool to determine if you're at a healthy weight, alongside other factors like waist circumference and overall health status. Your "correct" weight depends on your height, age, sex, and individual health circumstances, which is why one-size-fits-all targets don't work. This guide explains how to calculate your healthy weight range using NHS guidance and the tools available to you.
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 to Calculate Your Healthy Weight in the UK
The NHS defines a healthy weight using BMI (Body Mass Index), which is calculated by dividing your weight in kilograms by your height in metres squared. For most UK adults, a healthy BMI falls between 18.5 and 24.9. However, if you are of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds — a healthy BMI for these groups starts at 18.5 and goes up to 22.9, as these populations face higher health risks at lower BMI levels.
To find your specific healthy weight range, use our free BMI calculator above — it instantly shows you where you sit on the NHS scale and what your healthy weight range is for your height. This is more accurate than aiming for a single target weight, as it accounts for natural variation in body composition.
Beyond BMI, the NHS also considers waist circumference: men should aim for under 94cm (37 inches), and women under 80cm (31.5 inches) for good health. Even if your BMI is in the healthy range, excess belly fat can still pose health risks, which is why waist measurement matters alongside weight.
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.
Understanding Your Personal Weight Target
Your "correct" weight is not necessarily what you weighed in your twenties — it's the healthy weight range for your current height and body composition. Use our free weight converter to easily switch between kilograms, stone, and pounds, so you can work with measurements you're familiar with. Many UK weight loss programmes and health apps use different units, so being able to convert instantly is invaluable.
If you're unsure whether your weight is healthy for you, your GP is the best starting point. They can assess your individual health context, any underlying conditions, and whether weight management would benefit you specifically. They may refer you to NHS weight management services if appropriate, or simply reassure you that your weight is healthy. Remember: two people at the same weight and height can have completely different body compositions and health needs, so personalised advice matters.
- 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 is the correct weight for my height in the UK?
The NHS defines correct weight using BMI. For your height, calculate your healthy weight range using our free BMI calculator above. A healthy BMI is 18.5–24.9 for most adults, or 18.5–22.9 for South Asian, Chinese, Black African, and Black Caribbean adults. Your GP can also advise on your personal healthy weight target.
How do I calculate my BMI correctly?
BMI = weight (kg) ÷ height (m)². For example, if you weigh 70kg and are 1.73m tall, your BMI is 70 ÷ (1.73 × 1.73) = 23.4, which is healthy. Use our BMI calculator on this page for instant, accurate results.
Is there one correct weight everyone should aim for?
No. Your correct weight depends on your height, age, sex, muscle mass, and health conditions. Two people of the same height and weight can have different body compositions. This is why BMI ranges are more useful than single target weights, and why your GP's personalised advice is valuable.
Does waist measurement matter as much as weight?
Yes. The NHS considers waist circumference alongside weight because excess belly fat increases health risks even if BMI is healthy. Men should aim for under 94cm, women under 80cm. A tape measure around your natural waist gives an additional health indicator beyond weight alone.
Should I use kilograms or stone to track my weight in the UK?
Either works — it's personal preference. Many UK adults prefer stone and pounds, while NHS clinical measurements use kilograms. Use our free weight converter to switch between units easily, then track progress in whichever measurement feels natural to you using our progress tracker.
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.