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
How Many Centimetres In A Litre?
You cannot directly convert centimetres to litres because they measure different physical properties. Centimetres measure length or distance, whilst litres measure volume or capacity. However, understanding these UK measurements is important for health tracking, particularly when recording body measurements and hydration intake as part of a weight management plan. MyWeightCheck provides clear guidance on measurements used for health monitoring and healthy weight management 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.
Why Centimetres And Litres Cannot Be Converted
Centimetres (cm) are units of length — they measure how long or tall something is. Litres are units of volume — they measure how much space something takes up or how much liquid it can hold. These are fundamentally different measurements, so a direct conversion between them is mathematically impossible.
- Centimetres: Used to measure height, waist circumference, chest size, and other body dimensions
- Litres: Used to measure liquid volume — water intake, milk, juice, or any fluid capacity
- Why the confusion: Both are metric units, which sometimes leads people to assume they can be converted
In UK health contexts, centimetres are commonly used for body measurements (particularly waist circumference, which is important for assessing cardiovascular health), whilst litres measure daily water or fluid intake — both important health metrics but never interchangeable.
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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.
Using Measurements For UK Health Assessment
When tracking health and weight management in the UK, you'll use centimetres for body measurements (height, waist circumference) and litres for fluid intake. Waist circumference measured in cm is particularly important: the NHS considers a waist over 94cm in men or 80cm in women to indicate increased health risk, regardless of BMI. Daily water intake is often tracked in litres — the NHS generally suggests drinking 6–8 glasses (approximately 1.2 litres) of fluid daily. Using our free BMI calculator and weight converter above helps ensure you're tracking health metrics accurately using correct UK measurements.
- 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.
Can you convert centimetres to litres?
No — centimetres measure length whilst litres measure volume. They are different physical properties and cannot be converted into one another. It's like trying to convert inches to gallons: the units measure fundamentally different things.
What are centimetres used for in health?
Centimetres measure body dimensions: height, waist circumference, hip circumference, and chest size. Waist measurement in cm is particularly important for NHS health assessment — a waist over 94cm (men) or 80cm (women) indicates increased cardiovascular risk.
What are litres used for in health?
Litres measure fluid volume — primarily water and drink intake. The NHS recommends approximately 1.2 litres (6–8 glasses) of fluid daily for adults. Tracking hydration in litres is part of healthy weight management.
Why do people confuse cm and litres?
Both are metric units, so people sometimes assume all metric units can convert to each other. However, any metric unit measures either length, mass, volume, temperature, or time — conversions only work between units measuring the same physical property.
How do UK health measurements work together?
UK health assessment combines multiple measurements: height and weight (for BMI using our free calculator), waist circumference in cm (for health risk), and fluid intake in litres (for hydration). Together, these give a complete picture of health status.
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.