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
Tracking Body Measurements in Centimetres — UK Health Guide
A cm tracker helps you monitor your body measurements in centimetres, a key metric used by the NHS and health professionals across the UK. Whether you're tracking height, waist circumference, or calculating your BMI, measuring in centimetres provides accurate, consistent data for assessing your health. This UK health guide explains how to measure correctly, what measurements matter most, and how tracking supports your wellness journey alongside lifestyle changes.
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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.
Key Measurements to Track in Centimetres
Height (centimetres): Measured from the top of your head to your heels, standing barefoot on a flat surface. Essential for BMI calculation and understanding healthy weight ranges. The average UK adult man is approximately 175.3 cm tall, while the average woman is around 161.6 cm.
Waist circumference: Measured at the narrowest point around your middle, just above your hip bones. The NHS considers this critical for cardiovascular health assessment — more important than weight alone. Increased waist measurement indicates greater health risk even at healthy BMI levels. Men should aim for under 94 cm; women under 80 cm.
Hip circumference: Measured around the widest part of your hips and buttocks. Used to calculate waist-to-hip ratio, which predicts health risk better than BMI for some populations.
Chest, arm, and thigh measurements: Useful for tracking body composition changes alongside weight, particularly if you're combining exercise with weight management.
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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 Centimetres Matter in UK Health Tracking
The NHS and UK health professionals use metric measurements (centimetres and kilograms) as standard, making centimetre tracking aligned with official UK health guidance. Our free BMI calculator uses height in centimetres to give you an accurate result, and tracking measurements over time reveals changes that weight alone might miss — particularly if you're building muscle or redistributing body composition.
Track progress beyond the scales: Even if your weight stays the same, reductions in waist circumference signal improving health. Conversely, weight increases combined with stable or decreasing waist measurements suggest positive body composition changes. This is why NHS health guides recommend tracking multiple measurements rather than relying on weight alone.
- 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's the best way to measure waist circumference accurately?
Stand relaxed with feet together. Place a soft measuring tape around your waist at the narrowest point, just above your hip bones. Keep the tape snug but not tight — it shouldn't compress the skin. Record the measurement in centimetres. Measure at the same time of day each week for consistency, ideally in the morning before eating.
How often should I track my measurements?
Once weekly is ideal — consistency matters more than frequency. Measure at the same day and time each week to account for daily fluid fluctuations. Many people find weekly tracking less discouraging than daily, while still showing meaningful progress. Our free progress tracker lets you log measurements and visualise changes over time.
Can I use a cm tracker if I'm using weight loss medication like Mounjaro or Wegovy?
Yes — measurement tracking is valuable alongside medication. Both height and waist measurements combined with your BMI provide a complete health picture. Our GLP-1 weight loss calculator helps project outcomes, while tracking actual waist circumference shows real progress. Always discuss measurement goals with your prescriber as part of your overall management plan.
What's the difference between tracking in centimetres versus inches?
Centimetres are the NHS standard and used throughout UK health guidance, making them ideal for comparing results with your GP or health professional. One inch equals 2.54 cm. Our weight converter tool switches between metric and imperial units, but NHS guidance uses centimetres, so tracking in cm aligns your measurements with official UK health thresholds.
Is tracking waist circumference more important than BMI?
Both matter — they measure different things. BMI tells you if weight is healthy for your height; waist circumference reveals where fat is stored, which affects cardiovascular risk. The NHS recommends tracking both. People with similar BMI but different waist measurements face different health risks. Combined with our free BMI calculator, waist tracking gives you complete insight into your health profile.
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.