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
What Is 12.5 Centimetres in Inches?
12.5 centimetres is equal to approximately 4.92 inches. This small measurement is commonly referenced in UK health contexts, including waist circumference assessments and medical examinations. Whether you're checking body measurements for health purposes or simply need a quick conversion, understanding metric and imperial measurements is useful for navigating NHS health guidance and personal fitness tracking in the UK.
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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 to Convert Centimetres to Inches
Converting centimetres to inches is straightforward using a simple formula: divide centimetres by 2.54. For 12.5cm, the calculation is 12.5 ÷ 2.54 = 4.92 inches.
- 1 centimetre = 0.3937 inches
- 1 inch = 2.54 centimetres
- For quick reference: 12.5cm falls between 4 inches and 5 inches
In UK health assessments, centimetres are the standard measurement for height and waist circumference. The NHS uses centimetres for clinical measurements, though many UK adults think in feet and inches for height. Our free weight converter helps you switch between metric and imperial measurements instantly for all your health tracking needs.
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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 Measurement Accuracy Matters for UK Health Assessment
Accurate body measurements are essential for health monitoring in the UK. Waist circumference—a key NHS health indicator—is measured in centimetres. The NHS recommends healthy waist measurements of under 80cm for women and under 94cm for men as a general guideline, though ethnicity-specific thresholds apply for some groups.
Taking consistent measurements at the same location and time helps track changes accurately. Use our free BMI calculator alongside waist measurement data for a fuller picture of your health status. Your GP can provide personalised guidance on what measurements mean for your individual health profile and recommend further assessment if needed.
- 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.
How many inches is 12.5 centimetres exactly?
12.5 centimetres equals 4.921 inches. In everyday terms, this is just under 5 inches. For quick conversions, multiply centimetres by 0.3937 to get inches, or divide inches by 2.54 to get centimetres.
Why do the NHS use centimetres instead of inches?
The NHS uses the metric system (centimetres and kilograms) for clinical consistency and international standardisation. However, many UK health resources provide both metric and imperial measurements to match how people naturally think about their measurements.
Is 12.5cm a typical measurement for any part of the body?
12.5cm is a relatively small measurement. It might represent a wrist circumference or small body part measurement. For health assessments, waist, hip, and chest circumferences are more commonly tracked and are usually larger (typically 60–120cm).
How accurate do my home measurements need to be?
For tracking progress, consistency is more important than perfect accuracy. Always measure at the same location and time of day (ideally morning), use the same measuring tape, and keep a record. Minor variations of 0.5–1cm are normal and not meaningful.
Where can I find NHS guidance on healthy body measurements?
The NHS website provides guidance on healthy weight ranges using BMI and waist circumference. Your GP can assess your personal measurements in context of your age, ethnicity, and health history. MyWeightCheck's free BMI calculator and weight converter tools support your tracking alongside professional advice.
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.