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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What Is a Healthy BMI for Men?
A healthy BMI for men in the UK is between 18.5 and 24.9 according to NHS guidelines. BMI (body mass index) is a simple screening tool that uses your height and weight to assess whether you're in a healthy weight range. However, it's important to understand what your BMI means, how it's calculated, and its limitations when considering your overall health. Use our free BMI calculator above to find your personal BMI instantly, and discover where you fall within the NHS categories.
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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.
UK BMI Categories and Ranges for Men
The NHS uses five BMI categories to classify adult weight status. A healthy BMI ranges from 18.5 to 24.9 for all men regardless of ethnic background. Below 18.5 is classified as underweight, which may indicate nutritional deficiency or other health concerns. A BMI of 25.0 to 29.9 falls into the overweight category — this threshold marks the point where health risks begin to increase. BMI 30.0 to 34.9 is classified as obese (Class I), 35.0 to 39.9 as obese (Class II), and 40.0 and above as severely obese (Class III).
- Underweight: Below 18.5
- Healthy weight: 18.5 – 24.9
- Overweight: 25.0 – 29.9
- Obese (Class I): 30.0 – 34.9
- Obese (Class II): 35.0 – 39.9
- Severely obese (Class III): 40.0+
To calculate your BMI using the standard BMI formula, divide your weight in kilograms by your height in metres squared (BMI = kg ÷ m²). For example, a man who is 1.75m tall and weighs 75kg would have a BMI of 24.5, placing him in the healthy weight range. You can also use our free weight converter to switch between metric and imperial measurements.
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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.
Important BMI Limitations and Complementary Health Measures
While BMI is a useful screening tool, it has significant limitations. BMI does not distinguish between muscle mass and fat mass — a man with substantial muscle may have a high BMI but low body fat, meaning BMI alone doesn't reflect true health status. BMI also ignores where fat is stored; abdominal fat carries greater health risks than fat stored elsewhere. Men should also measure waist circumference: increased risk begins at 94cm (37 inches), with high risk at 102cm (40 inches).
For the most accurate health assessment, combine BMI with waist-to-height ratio (healthy below 0.5), fitness level, and blood pressure. Your GP can provide personalised guidance on whether your BMI is appropriate for your individual health context, particularly if you're very muscular, elderly, or have chronic health conditions. If you're concerned about your health or weight, speak with your GP for professional advice tailored to your circumstances.
- 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 BMI?
Divide your weight in kilograms by your height in metres squared (BMI = kg ÷ m²). For example, at 80kg and 1.78m tall, your BMI would be 25.3. Our free BMI calculator above does this instantly — just enter your height and weight in your preferred units (stone, pounds, or kilograms).
Is a BMI of 25 considered healthy?
A BMI of 25 falls into the overweight category according to NHS guidelines — the healthy range is 18.5 to 24.9. A BMI of 25 means you're just above the healthy threshold. It's worth reviewing your lifestyle with your GP to discuss whether modest weight loss might reduce your health risks.
What's the average BMI for UK men?
According to ONS data, the average UK adult man has a BMI of approximately 27.9, which falls in the overweight category. The average UK man weighs around 85.7kg (13st 7lbs) and is 175.3cm (5ft 9in) tall. This reflects that many UK men are above the healthy BMI range.
Why doesn't BMI account for muscle?
BMI uses only height and weight — it can't distinguish between muscle and fat. Muscle is denser than fat, so muscular men may have a high BMI despite having low body fat. This is why BMI should be used alongside other measures like waist circumference and fitness level, not as the sole indicator of health.
What's the best way to lower an unhealthy BMI?
The NHS recommends losing weight gradually at 0.5 to 1kg per week through a reduced-calorie diet and increased physical activity. This typically requires a calorie deficit of around 500 calories per day. Your GP can refer you to weight management services, or you can start with free resources like the NHS Weight Loss Plan. Even losing 5–10% of your body weight brings health benefits.
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.