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
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How to Work Out Your Healthy Weight Range
Working out your healthy weight range is a practical first step in understanding your personal health. Using your height and NHS guidance, you can calculate the weight range where most adults experience better health outcomes. This UK health guide shows you exactly how to work out the range using simple maths, and explains what it means for your wellbeing. We'll cover the NHS approach, how BMI fits in, and how to use your results to set realistic health goals.
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.
Calculating Your Healthy Weight Range Using BMI
The easiest way to work out your healthy weight range is using BMI (Body Mass Index), the measure recommended by NHS guidance. A healthy BMI sits between 18.5 and 24.9 for most UK adults.
To work out the range for your height, use this formula:
- Lower bound: 18.5 × height (metres)²
- Upper bound: 24.9 × height (metres)²
For example, if you're 1.75m tall (5ft 9in): your healthy range is approximately 56.6kg to 76.2kg (8st 12lbs to 12st 0lbs). Our free BMI calculator above will work this out instantly for you — just enter your height and it shows your exact healthy weight range. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a slightly lower range: 18.5 to 22.9 BMI, reflecting higher health risks at standard thresholds.
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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.
Why Your Healthy Weight Range Matters
Knowing your healthy weight range helps you set realistic health goals rather than chasing an arbitrary number on the scales. Being within this range is associated with lower risk of type 2 diabetes, heart disease, and certain cancers. However, BMI is a screening tool with limitations — it doesn't account for muscle mass, bone density, or where fat is stored. A trained athlete might have a high BMI despite low body fat. Your GP can provide personalised nhs health advice about what weight is right for your individual circumstances, especially if you have existing health conditions. Use our free weight converter to switch between kg, stone, and pounds as you track your progress towards your healthy range.
- 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 work out my healthy weight range if I'm 5ft 6in tall?
Convert your height to metres (5ft 6in = 1.68m). Multiply 18.5 × (1.68)² = 52.2kg (lower), and 24.9 × (1.68)² = 70.2kg (upper). Your healthy range is approximately 52–70kg (8st 2lbs to 11st 0lbs). Use our BMI calculator to verify this instantly for your exact measurements.
Does my healthy weight range change if I'm Black African or South Asian?
Yes, the NHS recommends lower BMI thresholds (18.5–22.9 instead of 18.5–24.9) for adults of South Asian, Chinese, Black African, or Black Caribbean heritage. This reflects research showing these groups have higher disease risk at standard BMI levels. Your GP can discuss the right range for your background.
Is healthy weight range the same as ideal body weight?
Not exactly. Healthy weight range is based on BMI and health risk. Ideal body weight considers frame size and muscle mass using formulas like the Devine or Robinson method. Your GP can help determine what's ideal for you specifically, as healthy weight varies based on individual factors.
What if I'm outside my healthy weight range — should I lose or gain weight?
If you're above your healthy range, gradual weight loss of 0.5–1kg per week is recommended by the NHS, alongside diet and activity changes. If below, your GP should assess whether weight gain is needed. Never make rapid changes without professional guidance on your individual situation.
Can I use healthy weight range if I'm pregnant or have health conditions?
Healthy weight range calculations change during pregnancy and aren't appropriate for certain conditions. Always consult your GP or midwife for personalised nhs guidance. They'll advise on weight management appropriate for your specific circumstances and health history. ```
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.