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 the normal BMI range for men?
According to NHS guidelines, the normal or healthy BMI range for men (and all adults) is 18.5 to 24.9. This applies regardless of age or ethnicity — though some ethnic groups face higher health risks at lower BMI levels. Your BMI is calculated by dividing your weight in kilograms by your height in metres squared. A BMI within this range suggests a lower risk of weight-related health conditions. However, BMI is just one screening tool and doesn't account for muscle mass or where fat is stored. Use our free BMI calculator above to find your personal BMI instantly.
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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 BMI categories and what they mean
The NHS BMI categories divide adults into five groups based on health risk:
- Underweight: BMI below 18.5 — may indicate nutritional issues
- Healthy weight: BMI 18.5 to 24.9 — normal BMI range with lowest health risk
- Overweight: BMI 25.0 to 29.9 — increased risk of weight-related disease
- Obese Class I: BMI 30.0 to 34.9 — significant health risk
- Obese Class II: BMI 35.0 to 39.9 — high health risk
- Severely obese: BMI 40.0+ — very high health risk
For men of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends slightly lower BMI thresholds because these groups face higher diabetes and cardiovascular risk at the same BMI levels. For these groups, a healthy BMI range is 18.5 to 22.9 instead of 18.5 to 24.9.
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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.
NHS guidance on healthy weight and next steps
If your BMI formula result falls outside the healthy range, the NHS recommends starting with Tier 1 support: self-help using the NHS Weight Loss Plan, digital tools, or community programmes. Your GP can assess your overall health, not just your BMI, and discuss whether further support is needed. If you're overweight or obese with weight-related health conditions like type 2 diabetes or high blood pressure, your GP may refer you to specialist weight management services. Remember that BMI limitations mean it doesn't account for muscle, bone density, or fitness level — your GP can give you personalised advice about what your BMI means for your specific health. Try the weight converter on this page to switch between kg, stone, and lbs if you need to compare measurements.
- 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.
What BMI is considered normal for a man?
A normal or healthy BMI for men is 18.5 to 24.9 according to NHS guidelines. For men of South Asian, Chinese, Black African, or Black Caribbean heritage, the healthy range is slightly lower at 18.5 to 22.9 due to higher cardiovascular and diabetes risk at the same BMI. Your GP can advise if your BMI is healthy for you personally.
How do I calculate my BMI?
The BMI formula is: weight (kg) divided by height (metres) squared. For example, if you weigh 75kg and are 1.78m tall: 75 ÷ (1.78 × 1.78) = 23.7 BMI. Our free BMI calculator above does this instantly — just enter your weight and height in kg and cm.
What's the difference between BMI categories?
NHS BMI categories range from underweight (below 18.5) through healthy weight (18.5–24.9) to severely obese (40+). Each category reflects increasing health risk. A normal BMI range indicates lower risk of type 2 diabetes, heart disease, and certain cancers. However, BMI doesn't distinguish between muscle and fat.
Are BMI limitations important?
Yes — BMI limitations are significant. It doesn't account for muscle mass, so athletes may have high BMI but low body fat. It also ignores where fat is stored (waist measurement matters) and may be less accurate for elderly people or during pregnancy. Your GP considers your full health picture, not just BMI.
What should I do if my BMI is outside the healthy range?
If your BMI is above 24.9 (or 22.9 for some ethnic groups), speak to your GP. They'll assess your overall health, discuss lifestyle changes, and may refer you to NHS weight management support if needed. Small improvements — even 5–clinically studied weight loss — can significantly improve health.
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.