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 Does a BMI of 36 Mean?
A BMI of 36 falls into the obese category according to NHS guidelines. This means your weight may increase your risk of developing serious health conditions such as type 2 diabetes, heart disease, and high blood pressure. The good news is that even modest weight loss can improve your health significantly. Our free BMI calculator can help you understand your personal BMI and what it means for you, whilst our weight converter makes it easy to see your weight in stone, pounds, or kilograms.
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 Health Risk
According to NHS guidance, BMI is classified into the following BMI categories UK:
- Healthy weight: BMI 18.5–24.9
- Overweight: BMI 25.0–29.9
- Obese (Class I): BMI 30.0–34.9
- Obese (Class II): BMI 35.0–39.9
- Severely obese (Class III): BMI 40.0 and above
At a BMI of 36, you fall into Class II obesity. This is the category where health risks become more significant. The NHS recommends that people in this range seek support from their GP to discuss weight management options. It's important to note that BMI limitations exist—BMI does not distinguish between muscle and fat, so it is used as a screening tool alongside other health measures like waist circumference and overall fitness.
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.
NHS Weight Management Support and Next Steps
If you have a BMI of 36, the NHS recommends speaking with your GP as a first step. Your GP can assess your overall health, discuss any weight-related conditions you may have (such as high blood pressure or type 2 diabetes), and refer you to appropriate support. The NHS weight management pathway includes tier 1 self-help resources, tier 2 community-based programmes, and tier 3 specialist weight management services where prescription medications may be considered. Even a 5–10% reduction in body weight can significantly improve blood sugar control, reduce blood pressure, and lower your risk of heart disease. Use our GLP-1 weight loss calculator to explore what weight management support might look like for you.
- 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.
Is a BMI of 36 considered obese?
Yes, a BMI of 36 falls into Class II obesity according to NHS guidelines. Class II obesity refers to BMI between 35.0 and 39.9. This classification indicates an increased health risk and the NHS recommends seeking support from your GP to discuss weight management options tailored to your individual circumstances.
What health risks are associated with a BMI of 36?
A BMI of 36 increases your risk of type 2 diabetes, cardiovascular disease, high blood pressure, certain cancers, sleep apnoea, and osteoarthritis. However, the NHS emphasises that losing even 5–10% of your body weight can meaningfully reduce these risks and improve your health outcomes.
What is the healthy BMI range according to NHS guidance?
The NHS defines a healthy BMI range as 18.5 to 24.9. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a slightly lower healthy range of 18.5 to 22.9 due to higher health risks at lower BMI levels in these populations.
What should I do if my BMI is 36?
Contact your GP to discuss your weight and overall health. Your GP can assess whether you have any weight-related health conditions and refer you to NHS tier 2 or tier 3 weight management services. These services offer behaviour change support, dietary advice, and in some cases, prescription weight management medications. Use our free BMI calculator to understand your current BMI and track changes over time.
Can the BMI formula accurately assess my health at BMI 36?
The BMI formula provides a useful screening tool but has limitations. It does not account for muscle mass, bone density, or where fat is stored. At BMI 36, your GP may also measure your waist circumference and assess other health markers to get a complete picture of your health risk. This is why professional assessment is important.
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.