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 — Your UK Health Guide
Understanding your weight in relation to your height is one of the most important health measurements you can track. Your weight and height together determine your BMI (body mass index), which is the standard UK health screening tool used by the NHS to assess whether you're in a healthy weight range. Whether you're managing your weight, preparing for health changes, or simply want to understand where you stand health-wise, knowing how to calculate and interpret your measurements is essential for informed health decisions.
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 Together
Your weight and height are used together to calculate your BMI, a simple but powerful health indicator. BMI = weight (kg) ÷ height (m)² — this standard formula works for all UK adults regardless of age or background. The NHS uses BMI categories to screen for health risks: a healthy BMI is between 18.5 and 24.9, overweight is 25.0–29.9, obese (Class I) is 30.0–34.9, and severely obese is 40.0 and above. However, BMI has important limitations — it doesn't distinguish between muscle and fat, so athletes or very muscular individuals may have a high BMI despite low body fat. Additionally, for adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds due to higher cardiovascular risk at lower weights.
- Healthy BMI range: 18.5–24.9 (or 18.5–22.9 for South Asian and other specified groups)
- Waist circumference also matters: men over 94cm (37 inches) and women over 80cm (31.5 inches) have increased health risk, regardless of BMI
- Use our free BMI calculator above to find your instant BMI result and see which category you fall into
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.
Finding Your Healthy Weight Range and Taking Action
Once you know your height, you can calculate the healthy weight range recommended for you. For example, at 5ft 8in (173cm), a healthy weight is approximately 55–74kg (8st 9lbs to 11st 8lbs). If your current weight falls outside this range, even a 5–10% weight reduction can have significant health benefits, including lower blood pressure, improved blood sugar control, and reduced joint strain. The NHS recommends gradual weight loss of 0.5–1kg per week for sustainable results. Use our weight converter to switch between kg, stone, and pounds, and our progress tracker to log changes over time. If you need professional support, your GP can refer you to weight management services or discuss whether prescription treatments like GLP-1 injections might be suitable for your circumstances.
- 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 BMI using my weight and height?
BMI = weight in kilograms ÷ (height in metres)². For example, if you weigh 75kg and are 1.75m tall: 75 ÷ (1.75 × 1.75) = 24.5 BMI. Use our free BMI calculator on this page for gradual improvement — just enter your weight and height in your preferred units (kg, stone, or pounds; centimetres or feet and inches).
What weight and height combination is considered healthy in the UK?
According to NHS guidelines, a healthy BMI is 18.5–24.9 for most UK adults. For someone 5ft 8in (173cm) tall, this means weighing between roughly 55–74kg. However, healthy weight ranges vary by height and individual factors. Your GP can advise on what's healthy specifically for you, taking into account your age, sex, muscle mass, and medical history.
Is BMI accurate for everyone?
BMI is a useful screening tool but has limitations. It doesn't account for muscle mass (athletes may have high BMI but low body fat), age-related muscle loss, pregnancy, or where fat is stored on your body. Waist circumference is also important — over 94cm (men) or 80cm (women) indicates increased health risk. Your GP can provide personalised assessment beyond BMI alone.
How do I convert my weight and height between UK and metric measurements?
Use our free weight converter on this page to instantly switch between kilograms, stone, and pounds. For height: 1 inch = 2.54cm, or roughly: 5ft 8in = 173cm, 5ft 10in = 178cm. Most UK health services use kilograms and centimetres, so converting helps you understand NHS guidance and health literature.
What's the healthy weight range for my height?
Multiply your height in metres by itself, then multiply by 18.5 (lower healthy BMI) and 24.9 (upper healthy BMI). At 1.70m: healthy weight is 53–72kg (8st 5lbs to 11st 3lbs). At 1.80m: it's 60–81kg (9st 6lbs to 12st 10lbs). Use our free BMI calculator above to find your personal healthy range instantly, then use our progress tracker to monitor your journey if you're working towards a health goal.
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.