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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BMI Visualizer: See Your BMI Category Explained
A BMI visualizer helps you understand where your weight sits on the NHS BMI scale and what that means for your health. Instead of just seeing a number, a visual representation shows you exactly how your BMI compares to healthy, overweight, and obese categories. This guide explains how to use a BMI visualizer, what the different ranges mean, and why context matters beyond the number itself.
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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 BMI Categories Work in the UK
The NHS uses a standardised BMI formula to assess weight health in adults: weight (kg) divided by height in metres squared. The BMI formula produces a single number that falls into one of five main bmi categories uk:
- Underweight: BMI below 18.5
- Healthy weight: BMI 18.5–24.9 (the healthy bmi range)
- Overweight: BMI 25.0–29.9
- Obese Class I: BMI 30.0–34.9
- Obese Class II: BMI 35.0–39.9
- Severely obese: BMI 40.0 and above
A visual BMI visualizer displays these bmi range uk categories as a colour-coded scale, making it instantly clear where your personal BMI falls. Use our free BMI calculator above to check your personal BMI and see it positioned within these official NHS categories in seconds.
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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.
Why BMI Alone Isn't the Whole Picture
While a bmi calculator is useful, the BMI formula has important bmi limitations that a visualizer can't show. BMI doesn't distinguish between muscle and fat — a person with high muscle mass may have a high BMI despite low body fat. BMI also doesn't account for where fat is stored (belly fat carries higher health risks), age-related muscle loss, or ethnicity differences. For South Asian, Chinese, Black African, and Black Caribbean adults, the nhs bmi thresholds are lower because these groups face higher health risks at the same BMI. Your GP can interpret your BMI in the context of your complete health picture, including waist circumference, blood pressure, and blood sugar levels.
- 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 the exact healthy BMI range according to NHS guidelines?
The healthy BMI range is 18.5 to 24.9 for most adults. For South Asian, Chinese, Black African, and Black Caribbean adults, the healthy range is 18.5 to 22.9 due to higher cardiovascular risk at higher BMI levels. Your GP can advise on your individual healthy weight range.
Is overweight BMI the same as the obese BMI threshold?
No. Overweight BMI is 25.0–29.9, while the obese threshold starts at BMI 30.0. The overweight bmi threshold begins at just 25, so many people are in the overweight category without being classified as obese. Both categories may benefit from weight management support.
Can a BMI visualizer tell me if I need to lose weight?
A BMI visualizer shows where you sit on the NHS scale, but it's not a personal recommendation. Your GP considers your BMI alongside your health history, waist circumference, blood pressure, and fitness level before advising on weight management. Schedule a GP appointment to discuss your individual health goals.
Why do people of different ethnicities have different BMI categories?
Research shows that South Asian, Chinese, Black African, and Black Caribbean adults develop type 2 diabetes and cardiovascular disease at lower BMI levels than other populations. The NHS recommends adjusted thresholds for these groups to reflect their individual health risk profiles.
What's more important — BMI or waist circumference?
Both matter. A healthy BMI combined with a healthy waist circumference is the best indicator. Waist circumference indicates belly fat, which carries higher health risks. Men should aim for under 94cm (37 inches); women under 80cm (31.5 inches). Track your progress with our free progress tracker alongside BMI measurements.
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.