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
Height and Weight Calculator for UK Adults
A height and weight calculator helps you understand your current health position quickly and accurately. By entering your height and weight, you can instantly determine your BMI (body mass index), see where you fall on the NHS health scale, and identify your personal healthy weight range. Whether you're tracking your health, planning weight management, or simply curious about your metrics, these calculations provide a solid foundation for informed health decisions. Our free BMI calculator above does this instantly using UK measurements (stone, pounds, or kilograms).
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.
How Height and Weight Measurements Work Together
Your height and weight are the two key measurements needed to calculate BMI, the most widely used health screening tool in the UK. BMI = weight (kg) ÷ height (m)² — a simple formula that helps identify whether your weight falls within a healthy range for your height.
- Height is typically measured in centimetres or feet and inches in the UK
- Weight is measured in kilograms, stone, or pounds depending on your preference
- The ratio between these two measurements reveals whether your weight is healthy, overweight, or obese according to NHS guidelines
According to NHS guidance, a healthy BMI is between 18.5 and 24.9 for most adults. However, for adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds (18.5 to 22.9) because these groups face higher health risks at the same BMI. Use our free weight converter to switch between kg, stone, and pounds if you need to work in different units.
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.
Understanding Your Results and Taking Action
Once you've calculated your height and weight metrics, the next step is understanding what they mean for your health. A BMI in the healthy range (18.5–24.9) suggests good weight management; overweight (25–29.9) or obese categories (30+) indicate that lifestyle changes or medical support may help reduce health risks.
Important: BMI is a screening tool only — it doesn't account for muscle mass, bone density, or where fat is stored. Your waist circumference also matters; NHS guidance recommends men keep waist under 94cm and women under 80cm. If you're considering weight management options, our free GLP-1 weight loss calculator can help you explore projected outcomes with evidence-based approaches. Your GP can provide personalised guidance based on your individual health profile.
- 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 difference between BMI and healthy weight range?
BMI is a single number (your weight divided by height squared) that places you in a category. Healthy weight range is the span of weights that would give you a healthy BMI for your specific height. For example, at 5ft 8in, the healthy weight range is roughly 55–75kg. Both are useful, but range gives you flexibility.
Why do South Asian and Black African adults have different BMI thresholds?
Research shows these groups develop weight-related health conditions like type 2 diabetes at lower BMI levels than white European populations. The NHS therefore recommends lower thresholds (18.5–22.9 instead of 18.5–24.9) to catch health risks earlier and enable timely intervention.
Should I use kilograms or stone for my height and weight calculation?
Either works — the calculator handles both. Most UK adults find stone and pounds more familiar for body weight, whilst healthcare professionals often use kilograms. Convert using our free weight converter if you need to switch between units.
My BMI is 28 but I feel healthy — does that mean the calculation is wrong?
BMI is a screening tool, not a diagnosis. A BMI of 28 falls in the overweight category, but BMI doesn't account for muscle mass, fitness, or genetics. Your GP can assess your individual health holistically. If you have weight-related health concerns, your doctor can advise on next steps.
Can I use a height and weight calculator to track weight loss progress?
Yes — recalculating your BMI as you lose weight shows progress numerically. However, our free progress tracker is designed specifically for tracking weight loss over time, recording weekly changes and visualising your journey towards your goal weight.
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.