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 Healthy BMI for Men in the UK?
A healthy BMI for adult men in the UK is between 18.5 and 24.9, according to NHS guidelines. This range indicates a weight that's associated with lower health risks. However, BMI is just one measure of health—it doesn't account for muscle mass, bone density, or where fat is stored on your body. Your GP can provide personalised guidance about what a healthy weight means for you personally. Use our free BMI calculator above to check your personal BMI instantly and see where you fall on the NHS scale.
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.
NHS BMI Categories and What They Mean
The NHS BMI formula divides your weight in kilograms by your height in metres squared. For men, the standard BMI range uk categories are:
- Below 18.5: Underweight
- 18.5 to 24.9: Healthy weight
- 25.0 to 29.9: Overweight
- 30.0 to 34.9: Obese (Class I)
- 35.0 to 39.9: Obese (Class II)
- 40.0+: Severely obese (Class III)
These bmi categories uk are based on research linking BMI to health risks. A healthy BMI of 18.5–24.9 is associated with lower risk of type 2 diabetes, heart disease, and certain cancers. However, it's important to understand that bmi limitations exist—athletes with high muscle mass may have a higher BMI but low body fat, and BMI doesn't measure visceral fat (fat around organs), which carries greater health risks. Your GP can assess your individual health based on multiple factors beyond BMI alone.
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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.
NHS Weight Management Support and Next Steps
If your BMI falls outside the healthy range, the NHS offers support through its weight management pathway. Tier 1 includes self-help resources and digital tools like our free BMI calculator. Tier 2 offers GP-led behaviour change programmes. Tier 3 provides access to specialist weight management services where your GP can refer you. Your GP can also assess whether prescription weight loss treatment might be appropriate if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions like high blood pressure or type 2 diabetes. The NHS recommends losing weight gradually at 0.5–1 kg per week for sustainable results.
- 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's the difference between healthy BMI and overweight BMI for men?
A healthy BMI is 18.5–24.9, while the overweight threshold starts at 25.0 according to NHS guidelines. Men with a BMI of 25–29.9 are classified as overweight, meaning they have a modestly increased health risk compared to the healthy range. However, some overweight men with good fitness levels and no weight-related health conditions may still be healthy—your GP can advise you personally.
How do I calculate my BMI as a man in the UK?
Use the BMI formula: weight (kg) divided by height (metres) squared. For example, a man weighing 80kg and 1.75m tall would calculate: 80 ÷ (1.75 × 1.75) = 26.1 BMI. Our free weight converter can help you convert stone and pounds to kilograms, and our BMI calculator above does the calculation instantly for you.
Can BMI be inaccurate for men with muscle?
Yes—BMI doesn't distinguish between muscle and fat. A muscular man may have a higher BMI but lower body fat percentage than the healthy range suggests. Your GP or a fitness professional can assess your body composition more accurately using other measurements like waist circumference or body fat percentage tests.
At what BMI should I see my GP about weight management?
The NHS recommends discussing weight with your GP if your BMI is 25 or above, especially if you have health conditions like high blood pressure, type 2 diabetes, or sleep apnoea. If your BMI is 30 or above, your GP can refer you to specialist weight management services. Don't wait—early support is more effective than waiting until BMI reaches severe obesity.
What does the NHS recommend for healthy weight loss?
The NHS recommends losing weight gradually at 0.5–1 kg (1–2 lbs) per week through a combination of reduced-calorie diet and increased physical activity. A sustainable approach is usually more successful than gradual weight management. Our free progress tracker can help you log your weight loss journey, and your GP can refer you to specialist services if you need additional support.
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.