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
How Much Weight I Need To Lose — UK Calculator
Your healthy weight depends entirely on your height, age, and individual body composition — not a fixed number. According to NHS guidance, a healthy weight corresponds to a BMI of 18.5 to 24.9. Use our free BMI calculator above to discover your personal healthy weight range instantly. This guide shows you the ideal weight for your height in both kg and stone, so you can understand what a healthy weight range looks like for your body.
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.
Healthy Weight Range By Height — UK Table
Below is a practical healthy weight range for adults across common UK heights. These figures are based on an NHS healthy weight BMI range of 18.5–24.9. Remember: these are ranges, not targets. Where you sit within this range depends on muscle mass, frame size, and overall fitness.
- 5ft 0in (152cm): 47–63 kg (7st 5lbs–9st 13lbs)
- 5ft 2in (157cm): 50–67 kg (7st 12lbs–10st 7lbs)
- 5ft 4in (163cm): 53–71 kg (8st 5lbs–11st 2lbs)
- 5ft 6in (168cm): 56–75 kg (8st 12lbs–11st 11lbs)
- 5ft 8in (173cm): 59–79 kg (9st 4lbs–12st 6lbs)
- 5ft 10in (178cm): 63–84 kg (9st 13lbs–13st 3lbs)
- 6ft 0in (183cm): 66–89 kg (10st 5lbs–14st 0lbs)
Use the weight converter on this page to check any of these values in your preferred units.
Clinically BackedWeight Loss
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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.
Individual Factors That Affect Your Healthy Weight
Your ideal weight range is personal and influenced by factors beyond just height and BMI. Muscle mass: athletes and people with more muscle weigh more but may have lower body fat. Frame size: some people naturally have larger bone structure. Age: muscle loss with age means older adults may need different targets. Ethnicity: the NHS recommends lower BMI thresholds for South Asian, Chinese, Black African, and Black Caribbean adults (18.5–22.9 is healthy, rather than 18.5–24.9) because these groups have higher health risks at the same BMI. Your GP can discuss what a healthy weight range means specifically for you.
- 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 how much weight I need to lose?
Subtract your current weight from the upper limit of your healthy weight range. For example, if you're 5ft 6in and weigh 85kg, your healthy range is 56–75kg. You would need to lose around 10kg to reach the upper end of that range. However, losing even 5–10% of your body weight brings significant health benefits. Track your progress using our free progress tracker tool.
Is the healthy weight range the same for men and women?
No. The healthy BMI range (18.5–24.9) is the same, but because women typically have less muscle mass than men, the actual weight for a given height is often slightly lower for women. However, individual variation is more significant than gender alone. Your GP can advise what's healthy for you specifically.
What if I'm very muscular — will BMI be inaccurate?
Yes. BMI does not distinguish between muscle and fat. If you're athletic or strength-train regularly, you may have a higher BMI but low body fat percentage — this is healthy. Conversely, someone with high BMI may have excess body fat. Use our BMI calculator as a screening tool, but discuss your individual health with your GP rather than relying on BMI alone.
How quickly should I try to lose weight?
The NHS recommends losing weight at a rate of 0.5–1 kg (1–2 lbs) per week for sustainable results. Faster weight loss can happen with medical support but increases the risk of muscle loss and nutritional deficiency. If you're considering prescription weight loss medication like Mounjaro or Wegovy, these are used alongside dietary changes and exercise — your prescriber will discuss realistic timescales for your situation.
Can I use a weight loss calculator to predict my results?
Weight loss calculators can estimate outcomes based on calorie deficit or medication trials, but individual results always vary significantly. Our free GLP-1 weight loss calculator can help estimate potential weight loss with prescription medications, based on clinical trial data — but real-world results depend on your diet, activity, metabolism, and consistency.
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.