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 Height-Waist Ratio and Why Does It Matter?
Your height-waist ratio is a simple measurement that compares your waist circumference to your height, and it's one of the most accurate predictors of cardiovascular health and weight-related risks. The NHS recommends keeping your waist-to-height ratio below 0.5 for all UK adults, regardless of BMI. This measurement matters because it shows where fat is stored on your body — belly fat carries greater health risks than fat stored elsewhere. Unlike BMI alone, which doesn't distinguish between muscle and fat, your height-waist ratio provides valuable insight into your body composition and metabolic health. Use our free BMI calculator alongside this measurement for a complete picture of your health.
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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 Calculate Your Height-Waist Ratio
Calculating your height-waist ratio is straightforward and requires just two measurements: your waist circumference and your height.
Step 1: Measure Your Waist Stand upright and find the narrowest part of your waist, typically just above your hip bones. Measure across your skin using a soft measuring tape — not over clothing. Record this measurement in centimetres.
Step 2: Measure Your Height Stand barefoot against a wall with your heels touching the wall. Measure from the top of your head to the floor using a measuring tape or marked doorframe. Record in centimetres.
Step 3: Calculate the Ratio Divide your waist circumference by your height. For example, if your waist is 80cm and your height is 170cm, your ratio is 80 ÷ 170 = 0.47. A ratio below 0.5 is considered healthy according to NHS guidance. This simple calculation is more predictive of cardiovascular disease risk than BMI alone, making it an essential health metric for UK adults.
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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.
Understanding Your Height-Waist Ratio Results
Healthy ratio: Below 0.5 — This indicates a lower risk of weight-related health conditions including heart disease, stroke, type 2 diabetes, and metabolic syndrome. Most UK health guidelines recommend maintaining a ratio below 0.5 as a target.
At-risk ratio: 0.5 or above — A ratio of 0.5 or higher suggests central obesity (excess fat around the abdomen), which carries increased metabolic and cardiovascular risks even if your BMI appears normal. This is important because abdominal fat is metabolically active and linked to inflammation.
Your height-waist ratio works alongside other measurements — use our free weight converter to track changes in kg or stone, and combine this with your BMI using our BMI calculator for comprehensive health monitoring. Central obesity can exist at any BMI level, making this measurement valuable for all UK adults concerned about their health.
- 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 height-waist ratio more accurate than BMI?
Height-waist ratio and BMI measure different things. BMI indicates overall weight status, while height-waist ratio specifically shows where fat is stored. Neither is perfect alone — together they give a complete picture. Height-waist ratio is particularly useful because it identifies central obesity, which carries greater health risks than fat stored elsewhere, even at normal BMI levels.
What's the NHS recommended height-waist ratio for UK adults?
The NHS recommends keeping your waist-to-height ratio below 0.5 for all UK adults. This applies regardless of age, gender, or ethnicity. A ratio below 0.5 is associated with lower cardiovascular and metabolic disease risk. If your ratio is 0.5 or above, discussing lifestyle changes with your GP is recommended.
Can I have a healthy BMI but an unhealthy height-waist ratio?
Yes, this is possible. You can have a BMI in the healthy range but still carry excess central abdominal fat, indicated by a height-waist ratio above 0.5. This is sometimes called "metabolically obese normal weight" and still increases health risks. This is why using both measurements together is valuable.
How often should I measure my height-waist ratio?
Measure every 4–8 weeks if you're focused on health changes or weight management. This allows time to see meaningful changes from lifestyle modifications. Monthly measurements are reasonable during active weight loss or health intervention programmes. For maintenance, quarterly checks are sufficient.
Does height-waist ratio apply to children and teenagers?
Height-waist ratio measurements are designed for adults. Children and teenagers require age and sex-specific assessments using growth charts, not adult ratio thresholds. If you're concerned about a young person's weight or health, your GP or a paediatrician should provide specific guidance using appropriate NHS growth reference charts.
Ready to take control of your weight loss journey?
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