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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Weight And Height BMI Chart Explained
A weight and height BMI chart shows the relationship between your body weight and height to calculate your Body Mass Index (BMI) — a key health screening tool used by the NHS. BMI helps identify whether your weight falls into a healthy range for your height. This guide explains how to read a BMI chart, what the different categories mean, and how to use it to understand your personal health context. The BMI formula is simple but understanding the ranges and their limitations is essential for making sense of your results.
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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 Read A Weight And Height BMI Chart
A weight and height BMI chart displays the BMI formula in action: BMI = weight (kg) ÷ height (m)². Charts typically show weight on one axis and height on the other, with colour-coded zones for different BMI categories. To use a chart, find your height on one side, locate your weight on the other, and follow the grid lines to where they meet — that point shows your BMI and category.
The standard NHS BMI range divides adults into five categories:
- Underweight: BMI below 18.5
- Healthy weight: BMI 18.5–24.9
- Overweight: BMI 25.0–29.9
- Obese (Class I): BMI 30.0–34.9
- Severely obese (Class III): BMI 40.0 and above
For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds — a healthy BMI starts at 18.5 but the overweight threshold drops to 23.0. Use our free BMI calculator above to calculate your exact BMI instantly rather than estimating from a chart.
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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.
BMI Limitations And What Else Matters
While a weight and height BMI chart is a useful bmi categories uk screening tool, it has important limitations. BMI does not distinguish between muscle and fat — athletes with high muscle mass may have a high BMI but low body fat. It also ignores where fat is stored; waist circumference is equally important. BMI limitations are especially relevant for older adults, pregnant women, and very muscular individuals.
The NHS recommends measuring your waist as well: men over 94cm (37in) have increased risk; women over 80cm (31.5in) have increased risk. Talk to your GP about what your personal BMI and measurements mean for your health — they can assess your individual risk factors and provide personalised guidance.
- 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 healthy BMI range according to NHS guidelines?
The NHS defines healthy weight as a BMI between 18.5 and 24.9 for most adults. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the healthy range is 18.5 to 22.9 due to higher health risks at lower BMI levels in these populations.
How accurate is a weight and height BMI chart?
BMI charts are reasonably accurate for population screening but not perfect for individuals. They work well for average adults but don't account for muscle mass, bone density, or fat distribution — factors that affect actual health risk.
Can I use a BMI chart if I'm pregnant or very muscular?
BMI charts are less reliable during pregnancy and for very muscular individuals (including athletes). Pregnant women should consult their midwife for guidance. Athletes may have high BMI due to muscle, not excess fat. Your GP can provide more appropriate assessment.
What should I do if my BMI is in the overweight category?
If your BMI is 25–29.9, consider discussing it with your GP, especially if you have weight-related health conditions like high blood pressure or type 2 diabetes. Gradual lifestyle changes — reduced-calorie diet and increased physical activity — typically help. Track your progress with our free progress tracker.
Is waist measurement as important as BMI?
Yes. Waist circumference indicates where fat is stored, which matters for health risk. Even people with a "healthy" BMI may have increased risk if they carry excess fat around the abdomen. The NHS recommends measuring both BMI and waist for a complete 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.