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 Normal Body Mass Index for Male?
A normal body mass index for men in the UK falls between 18.5 and 24.9 according to NHS guidelines. This range indicates a healthy weight relative to height and is associated with lower risk of weight-related health conditions. However, BMI is just one measure of health — your individual results depend on factors like age, fitness level, and where your body stores fat. Use our free BMI calculator above to find your personal BMI instantly, then read on to understand what your result means.
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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.
How to Interpret Your BMI Calculator Results
When you use the BMI calculator on this page, your result will fall into one of five main categories. A score between 18.5 and 24.9 is considered healthy weight for men of most backgrounds. If your result falls between 25 and 29.9, this is classified as overweight; 30 to 34.9 is obese (Class I); 35 to 39.9 is obese (Class II); and 40 or above is severely obese (Class III).
However, if you are of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a lower threshold — a healthy BMI range begins at 18.5 but sits at 22.9 at the upper end, reflecting your higher risk of type 2 diabetes and heart disease at the same weight as other populations.
- Score 18.5–24.9 = healthy weight
- Score 25–29.9 = overweight
- Score 30+ = obese (further subdivided by class)
- Ethnicity-adjusted thresholds apply to some groups
Your GP can help interpret your personal result and discuss any health concerns.
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.
BMI vs Body Composition — Which Matters More?
While BMI is a useful screening tool, it has significant limitations. BMI does not distinguish between muscle mass and fat mass — a muscular man or athlete may have a BMI in the "overweight" range yet have low body fat percentage. Body composition, measured by body fat percentage or lean body mass, often gives a clearer picture of health than BMI alone.
For a more complete assessment, consider both metrics: track your BMI using our calculator, and if possible, also measure your body fat percentage and waist circumference. A waist measurement above 94 cm (37 inches) increases health risk in men, even at a healthy BMI. This combined approach gives you a fuller understanding of your health status than BMI by itself.
- 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 is considered a normal BMI for an adult male in the UK?
According to NHS guidelines, a normal or healthy BMI for adult men is between 18.5 and 24.9. If you are of South Asian or Black African heritage, the upper limit is 22.9. Use our free BMI calculator above to find your personal score instantly.
Can I have a healthy BMI but unhealthy body composition?
Yes. BMI doesn't measure muscle versus fat, so a muscular man may have a BMI above 24.9 yet low body fat percentage. Body composition analysis and waist measurement provide additional health insights beyond BMI alone.
What's the difference between BMI and body fat percentage?
BMI is a weight-to-height ratio. Body fat percentage measures the actual proportion of fat tissue. BMI is quick to calculate but ignores muscle mass; body fat percentage is more specific but requires professional measurement or estimation.
How do I know if my BMI is healthy for my age?
BMI categories don't change with age — a healthy BMI remains 18.5–24.9 for adult men. However, your GP may consider age-related factors like muscle loss or health conditions when assessing your overall health.
Is waist measurement as important as BMI?
Yes. The NHS recommends measuring waist circumference alongside BMI. A waist above 94 cm (37 inches) increases cardiovascular and diabetes risk in men, even at a healthy BMI, so both measures matter for your health picture.
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.