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
Weight for Height Calculator — Discover Your Healthy Range
A weight for height calculator helps you determine if your current weight falls within a healthy range for your height according to NHS guidelines. Rather than relying on arbitrary numbers, the best way to assess whether your weight is healthy is to calculate your Body Mass Index (BMI) — a measurement that combines both your weight and height to give you a personalised health indicator. Our free BMI calculator on this page instantly shows you where you sit on the NHS health scale and helps you understand what your weight means for your long-term wellbeing.
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 Weight and Height Work Together
Weight alone tells you very little about health — two people weighing the same can have completely different body compositions depending on their height and muscle mass. This is why NHS guidance uses BMI (Body Mass Index) as the primary screening tool to assess healthy weight.
BMI is calculated by dividing your weight in kilograms by your height in metres squared. The NHS classifies BMI into clear ranges:
- Under 18.5: Underweight
- 18.5 to 24.9: Healthy weight
- 25.0 to 29.9: Overweight
- 30.0 and above: Obese
For adults of South Asian, Chinese, Black African, or Black Caribbean backgrounds, NHS guidance recommends lower thresholds — a healthy BMI starts at 18.5 but extends only to 22.9 for these groups, as they face higher health risks at the same BMI levels.
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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.
Finding Your Healthy Weight Range
Once you know your BMI, you can work backwards to find the healthy weight range for your specific height. For example, if you're 5ft 8in (173cm) tall, a healthy BMI of 18.5 to 24.9 means your healthy weight range is approximately 55kg to 74kg (8st 10lbs to 11st 10lbs). Everyone's ideal weight within that range depends on factors like muscle mass, bone density, and frame size — your GP can offer personalised guidance.
Use our free weight converter above to instantly switch between kilograms, stone, and pounds, and our BMI calculator to find exactly where your current weight sits. Remember, BMI is a screening tool but doesn't account for muscle mass — always discuss your personal health with your GP.
- 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 my weight and my healthy weight range?
Your current weight is what you weigh now; your healthy weight range is the weight bracket recommended by NHS guidelines for your specific height and age, based on BMI. A healthy BMI is 18.5 to 24.9 for most UK adults. Your actual ideal weight within that range depends on your muscle mass, bone density, and overall health — not just the number on the scales.
How do I calculate my healthy weight for my height?
Use the BMI calculator on this page, or multiply your height in metres squared by 18.5 (lower bound) and 24.9 (upper bound). For example, at 1.73m tall: lower = 18.5 × (1.73)² = 55.4kg; upper = 24.9 × (1.73)² = 74.5kg. Our free weight converter helps you switch between kg, stone, and pounds instantly.
Is BMI the only way to know if I'm a healthy weight?
BMI is the main NHS screening tool but has limitations — it doesn't distinguish muscle from fat. Waist circumference is also important: men over 94cm and women over 80cm have increased health risks. Your GP can assess your overall health picture, including fitness, family history, and any weight-related health conditions, to give you personalised advice.
Why do South Asian and Black African adults have different healthy weight ranges?
NHS guidance recommends lower BMI thresholds (18.5 to 22.9 instead of 24.9) for South Asian, Chinese, Black African, and Black Caribbean adults because research shows these groups face higher risks of type 2 diabetes and cardiovascular disease at the same BMI levels as European populations. This reflects genetic and metabolic differences.
Can I use a weight for height calculator if I'm pregnant or very muscular?
BMI and weight-for-height calculators are less accurate during pregnancy and for very muscular individuals (including athletes) because they don't account for extra pregnancy weight or high muscle mass. If you're pregnant, discuss weight management with your midwife or GP. If you're very muscular, ask your GP about body composition assessment instead of relying on BMI alone.
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.