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
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Healthy Weight Calculator — NHS BMI Framework for UK Adults
A healthy weight for you depends on your height, age, and overall health — not just a single number. The NHS defines healthy weight using BMI (body mass index), which ranges from 18.5 to 24.9 for most UK adults. This guide explains how to find your personal healthy weight range, what the NHS recommends, and how BMI fits into the bigger picture of health. Use our free BMI calculator above to find where you fall right now, and discover what a healthy weight means for you.
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.
What Is a Healthy Weight Range According to the NHS?
The NHS defines healthy weight using BMI, a measurement that combines your weight and height. A BMI between 18.5 and 24.9 is considered healthy for most UK adults. However, your actual healthy weight range varies significantly depending on your height.
For example, a healthy weight range for someone 5ft 8in (173cm) tall is approximately 55–74 kg (8st 8lbs to 11st 8lbs). For someone 5ft 4in (163cm) tall, it's roughly 49–65 kg (7st 9lbs to 10st 3lbs). These ranges are calculated by applying the BMI formula to your specific height.
Important: BMI is a useful screening tool but has limitations. It doesn't distinguish between muscle and fat, so athletes or very muscular individuals may have a higher BMI while remaining healthy. Your GP can discuss what a healthy weight means for your individual circumstances, including any weight-related health conditions you may have.
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.
Using Your Height to Calculate Your Healthy Weight Range
To find your healthy weight range, use your height with the NHS BMI formula. The calculation is straightforward: a healthy BMI (18.5–24.9) multiplied by your height in metres, squared.
Use our free weight converter to switch between kilograms and stone if you prefer UK measurements. Once you know your healthy weight range in kg, you can instantly convert to stone and pounds — making it easier to track your progress and understand health guidance in whichever units feel most natural.
Remember that healthy weight isn't one-size-fits-all. Factors like age, muscle mass, bone density, and existing health conditions all play a role. Your GP can provide personalised advice about whether you're within a healthy range for 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 BMI range does the NHS consider healthy?
The NHS defines a healthy BMI as 18.5–24.9 for most UK adults. A BMI below 18.5 is underweight, 25–29.9 is overweight, and 30 and above is obese. However, people of South Asian, Chinese, Black African, or Black Caribbean heritage have different recommended thresholds due to higher health risks at lower BMI levels.
How do I calculate my healthy weight range for my height?
Use the BMI formula: healthy weight = BMI 18.5–24.9 multiplied by your height in metres squared. For example, if you're 1.73m tall, your healthy range is roughly 55–74 kg (8st 8lbs to 11st 8lbs). Use our free BMI calculator above to find your personalised range instantly.
What if my weight is outside the healthy range?
If your weight falls outside the healthy BMI range, talk to your GP. They can assess your individual health, discuss any weight-related conditions, and recommend next steps — which might include lifestyle changes, referral to a weight management service, or discussion of other support options.
Does healthy weight mean the same thing for everyone?
No. Healthy weight depends on height, age, muscle mass, genetics, and existing health conditions. BMI is a screening tool, not a definitive measure. Athletes may have higher BMI but remain healthy. Your GP can advise on what's healthy for you personally.
Can I use a healthy weight calculator to track weight loss?
Yes. Use our free progress tracker to log your weight over time and monitor movement towards your healthy weight range. Combine this with our BMI calculator to see how your BMI changes as you progress, which is helpful if you're working towards a health goal.
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.