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 is a suitable weight for you?
Your suitable weight depends on your height, age, sex, and overall health rather than a single number. In the UK, the NHS uses BMI (body mass index) as the primary screening tool to determine whether your weight falls within a healthy range. A suitable weight for most adults is one that gives a BMI between 18.5 and 24.9, though for people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a slightly lower range of 18.5 to 22.9. Rather than aiming for a specific number, focus on reaching a weight that supports your long-term health and wellbeing.
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.
Understanding your healthy weight range
Your suitable weight range is calculated using your height and BMI. The NHS health weight guidance suggests that adults with a BMI below 25 have the lowest health risks. To find your personal healthy weight range, multiply your height in metres by itself, then divide your target weight in kilograms by this number.
For example, if you are 1.73 metres tall (5ft 8in), your healthy weight range would be approximately 55 to 74 kilograms (8st 10lbs to 11st 10lbs). However, suitable weight also depends on factors beyond BMI: muscle mass, bone density, age, and existing health conditions all play a role.
- Use our free BMI calculator above to find your personal suitable weight range instantly
- Convert your weight between stone, pounds, and kilograms using our weight converter
- Remember that BMI does not account for muscle mass — athletes may have a higher BMI but lower body fat
Your GP can provide personalised advice about what a suitable weight means for your individual circumstances, especially if you have existing health conditions.
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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.
Factors affecting your suitable weight
A suitable weight is not one-size-fits-all. Your age, sex, genetics, muscle mass, and medical history all influence what weight is healthiest for you. Women typically have a higher body fat percentage than men at the same BMI, and muscle mass naturally decreases with age, meaning your suitable weight may shift throughout your life.
If you have weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea, your GP may recommend aiming for a weight loss of 5 to 10 per cent of your current body weight — even modest reductions can have significant health benefits. Our free progress tracker helps you monitor changes over time and celebrate small wins. For personalised UK health advice, always consult your GP or contact an NHS weight management service in your area.
- 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 suitable weight range?
Multiply your height in metres by itself, then find a BMI between 18.5 and 24.9 by using your BMI calculator. For example, at 1.75m tall, a suitable weight range is roughly 57–76kg. Your GP can also discuss your ideal range based on your health history.
Is suitable weight the same for men and women?
The BMI healthy weight range is the same, but men and women typically have different body compositions. Men usually carry less body fat than women at the same BMI. Your GP can advise what suitable weight means for your individual circumstances.
What if I'm overweight but feel healthy?
Even if you feel well, being overweight (BMI 25–29.9) increases your risk of type 2 diabetes, heart disease, and certain cancers. Talk to your GP about weight management options. Losing even 5 per cent of your body weight can improve health outcomes significantly.
Does muscle mass affect my suitable weight?
Yes. Muscle weighs more than fat, so athletes or very muscular individuals may have a higher BMI but lower body fat percentage. BMI is a screening tool, not a perfect measure. Your GP can assess your overall health beyond BMI alone.
What's the best way to reach my suitable weight?
The NHS recommends losing no more than 0.5–1kg per week through a balanced diet and increased physical activity. Our free progress tracker helps you monitor your journey. For medical support, ask your GP about NHS weight management services or specialist referral options in your area.
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.