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 Tall Are You — Why Height Matters for Your Health
Your height is one of the two most important measurements for understanding your health in the UK. It directly affects your BMI calculation, determines your healthy weight range, and helps your GP assess whether you're at risk of weight-related health conditions. Whether you're checking your BMI, converting your weight between stone and kilograms, or working with your healthcare team on weight management, knowing your exact height in both centimetres and feet and inches is essential. This guide explains why height matters and how to measure yourself accurately.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Height Matters for UK Health Assessments
Height is a fundamental input for calculating your BMI (Body Mass Index), which the NHS uses to assess whether you're in a healthy weight range. The formula is simple: BMI = weight (kg) ÷ height (m)². Even a small difference in height changes your healthy weight range significantly. For example, someone who is 5ft 6in (168cm) has a healthy weight range of roughly 50–68kg (7st 12lbs to 10st 10lbs), whilst someone 5ft 10in (178cm) has a healthy weight range of about 57–78kg (9st 0lbs to 12st 4lbs). This is why accuracy matters. Your height also determines your eligibility for certain weight management treatments and helps healthcare professionals assess your overall health risk. The NHS relies on BMI as a screening tool, and height is half of that equation. Even if you're tracking weight loss or considering GLP-1 medications like Mounjaro or Wegovy, your prescriber will need your precise height to assess your BMI eligibility and monitor your progress accurately.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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.
How to Measure Your Height Accurately
For accurate results, measure yourself without shoes against a flat wall, keeping your heels, back, and head against the wall. Use a ruler or spirit level horizontally at the top of your head and mark the wall, then measure the distance from the floor to your mark. Record this in both centimetres (for NHS and medical use) and feet and inches (for everyday UK reference). Recheck your measurement if possible, as small errors can affect BMI calculations. Height naturally decreases slightly with age due to spinal compression, so if you haven't measured yourself recently, it's worth checking again. Use our free BMI calculator above to see how your height and weight combine to give your personal BMI, and our weight converter to switch between metric and imperial measurements. Your GP can also measure you accurately during a health check if you're unsure.
- 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.
Does height affect how much weight I should lose?
Yes, significantly. Your target healthy weight range is based entirely on your height. Two people weighing the same amount might have very different health risks depending on their height. Your GP or a weight management service will use your height to set personalised targets and monitor progress. Use the BMI calculator on this page to see your healthy weight range based on your specific height.
How often does height change in adults?
Adult height typically remains stable, though it naturally decreases by approximately 1–2cm over a lifetime due to spinal disc compression and posture changes. This process accelerates slightly after age 40. If you're tracking weight management long-term, remeasuring every few years is sensible. Significant height loss can also indicate underlying health issues, so mention any major changes to your GP.
Why do GLP-1 medications like Mounjaro and Wegovy need my height?
Prescribers use your height (along with your weight) to calculate your BMI, which determines whether you're eligible for these medications. In the UK, you generally need a BMI of 30 or above, or 27–29.9 with weight-related health conditions. Your height is essential for accurate eligibility assessment and for monitoring how much weight you've lost during treatment.
What's the difference between measuring in centimetres and feet and inches?
Centimetres are the metric standard used by the NHS, GP surgeries, and for official health records and BMI calculations. Feet and inches are the traditional UK measurement used in everyday conversation. Both are equally valid—use whichever your healthcare provider requests. Our weight converter helps you switch between all units easily.
Can I estimate my healthy weight range without seeing my GP?
Yes. Calculate your BMI using our free BMI calculator on this page—simply enter your height and weight, and it will show you whether you fall within the NHS healthy weight range. However, your GP can provide personalised advice based on your individual health, medical history, and any weight-related conditions, especially if you're considering weight management treatment.
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.