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
What's the Correct Weight For My Height?
There's no single "correct" weight for any height — healthy weight depends on your individual body composition, muscle mass, and overall health. However, the NHS provides a healthy weight range based on BMI (body mass index) that can guide you. For UK adults, a BMI between 18.5 and 24.9 is considered healthy, though these thresholds vary slightly for people of South Asian, Chinese, Black African, or Black Caribbean heritage. Use our free BMI calculator above to find your personal healthy weight range instantly, or read on for detailed NHS guidance and practical context for your height.
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.
NHS Healthy Weight Ranges and BMI Guidance
The NHS defines healthy weight using BMI, which is calculated by dividing your weight in kilograms by your height in metres squared. A healthy BMI for most UK adults falls between 18.5 and 24.9, though your actual healthy weight depends entirely on your individual health profile.
For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds — a healthy BMI range of 18.5 to 22.9 — because research shows these groups face higher risks of type 2 diabetes and cardiovascular disease at the same BMI levels as other populations.
- Healthy BMI (18.5–24.9): Most UK adults in this range have lower health risks
- Overweight (BMI 25–29.9): Increased risk of weight-related health conditions
- Obese (BMI 30+): Significantly increased health risks
Rather than focusing on a single target weight, it's more helpful to aim for the healthy weight range for your height. Calculate your BMI now using the calculator on this page to see where you fall and what your healthy range is.
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.
Beyond BMI: Waist Measurement and Real-World Context
BMI is a useful screening tool but it doesn't account for muscle mass, bone density, or where your body stores fat. Two people at the same weight and height can have very different body compositions. That's why the NHS also recommends checking your waist circumference — increased health risk begins at 94cm (37 inches) for men and 80cm (31.5 inches) for women.
Your GP can give you personalised advice about what a healthy weight means for your specific circumstances, including any health conditions, medications, or family history. Don't aim for an arbitrary number — instead, focus on feeling energetic, maintaining steady weight, and passing basic health checks. Use our free weight converter to switch between kg, stone, and pounds as you track your progress, and our progress tracker to monitor changes over time.
- 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.
How do I calculate my healthy weight range for my height?
Use the BMI calculator on this page to find your healthy weight range instantly. Alternatively, multiply your height in metres by itself, then multiply by 18.5 (for the lower healthy bound) and by 24.9 (for the upper bound). For example, if you're 1.70m tall: lower bound = 18.5 × (1.70)² = 53.4kg; upper bound = 24.9 × (1.70)² = 71.9kg.
Is my healthy weight different if I'm very muscular or athletic?
Yes — BMI doesn't distinguish between muscle and fat, so athletes and very muscular individuals may have a high BMI despite low body fat. If this applies to you, discuss your personal healthy weight range with your GP rather than relying on BMI alone. Waist circumference is a better indicator of health risk in these cases.
Why is the healthy weight range lower for people of South Asian or Black African heritage?
Research shows that people of South Asian, Chinese, Black African, and Black Caribbean heritage face higher health risks from weight-related conditions at lower BMI levels than other populations. The NHS therefore recommends they aim for a BMI of 18.5–22.9 rather than 18.5–24.9. Your GP can advise you on what this means for your individual health.
What if I'm in the healthy BMI range but still don't feel well?
BMI is one indicator of health, not a complete picture. If you're in the healthy BMI range but experiencing fatigue, joint pain, or other concerns, speak to your GP. Health involves fitness, sleep, stress, nutrition quality, and overall wellbeing — not just weight. Your GP can help identify what might be affecting how you feel.
How quickly should I aim to reach my healthy weight range?
The NHS recommends losing weight at a rate of 0.5 to 1kg (1–2 lbs) per week for sustainable, healthy results. A calorie deficit of around 500 kcal per day typically supports this rate. Very gradual weight management can increase muscle loss and isn't sustainable. If you need support, your GP can refer you to NHS weight management services or discuss other options with you.
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.