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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Where To Measure My Waist: Correct Technique & NHS Guidance
Your waist measurement is an important health indicator that complements BMI and can reveal health risks that BMI alone may miss. The NHS recommends measuring your waist circumference as part of a healthy weight assessment, as where you carry weight matters significantly for your cardiovascular health. This guide shows you exactly where and how to measure your waist accurately, following NHS guidance, so you can track this key health metric alongside your weight management journey.
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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 Measure Your Waist Correctly: NHS Standard Method
To measure your waist accurately using the NHS standard method, follow these steps:
- Stand upright and relax — do not hold your breath or suck in your stomach
- Place a soft tape measure around your waist at the midpoint between your lowest rib and the top of your hip bone (your natural waist, not where your trousers sit)
- The tape should be snug but not tight — you should be able to fit one finger underneath
- Keep the tape horizontal and parallel to the ground all the way around
- Read the measurement at the point where the tape overlaps
- Take the measurement three times and use the average
Measure in the same location and at the same time of day each time for consistency. Morning measurement before eating is ideal. Record your measurement in centimetres — the NHS uses metric for clinical guidance on waist health.
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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.
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NHS Waist Circumference Health Thresholds For UK Adults
The NHS provides clear waist circumference thresholds that indicate health risk, independent of BMI:
- Men: under 94cm (37 inches) = low risk; 94–102cm (37–40 inches) = increased risk; over 102cm (40 inches) = high risk
- Women: under 80cm (31.5 inches) = low risk; 80–88cm (31.5–34.5 inches) = increased risk; over 88cm (34.5 inches) = high risk
These thresholds apply to UK adults of European descent. If you are of South Asian, Chinese, Black African, or Black Caribbean heritage, your GP may advise using lower thresholds, as these groups face higher cardiovascular risk at smaller waist measurements. Carrying excess weight around your abdomen (central obesity) is linked to increased risk of type 2 diabetes, heart disease, and stroke — making waist measurement a valuable health screening tool alongside BMI calculator assessments.
- 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.
Why is waist measurement important if I know my BMI?
BMI does not account for where fat is stored on your body. Two people with the same BMI can have very different health risks depending on whether they carry weight around their abdomen or hips. Abdominal fat is more strongly linked to heart disease and diabetes risk. The NHS recommends using waist measurement alongside BMI for a more complete health picture.
Should I measure my waist over clothing or on bare skin?
Measure on bare skin or thin clothing only — not over thick jumpers or layers. This ensures accuracy. If you measure over clothing, always measure over the same thickness of fabric each time so your measurements are consistent. Many people measure first thing in the morning before eating for the most reliable baseline.
What if my waist measurement is above the NHS threshold?
If your waist circumference is above the NHS recommended range, speak to your GP. They can assess your individual health and may recommend lifestyle changes such as increased physical activity and dietary adjustments. Even a modest reduction of 5% in body weight can improve health outcomes and reduce waist circumference.
How often should I measure my waist?
You can measure weekly or monthly — consistency matters more than frequency. Choose one day per week (such as Monday morning) and measure at the same time to track changes accurately. Combine waist measurement tracking with our free progress tracker for a complete view of your health journey.
Is waist-to-height ratio better than just waist circumference?
Waist-to-height ratio is a useful additional measure. A healthy ratio is below 0.5 (your waist circumference divided by your height in the same units). Some research suggests this is a strong predictor of cardiovascular risk. Discuss with your GP which measurements are most relevant for your personal health assessment and goals.
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.