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
What's the Right Weight for Your Height?
The right weight for your height depends on your individual health, muscle mass, and body composition — not just a single number. The NHS uses BMI (body mass index) and healthy weight ranges to help UK adults understand whether their weight falls within a healthy zone for their height. Our free BMI calculator above can instantly show you where you stand, and we'll explain what it means and how to find your personal healthy weight range.
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.
NHS Healthy Weight Ranges by Height
The NHS defines a healthy weight as a BMI between 18.5 and 24.9 for most UK adults. However, the right weight for your height isn't a fixed number — it's a range. For example, at 5ft 8in (173cm), a healthy weight range is approximately 55–74 kg (8st 10lbs to 11st 8lbs). At 5ft 4in (163cm), the healthy range is roughly 48–64 kg (7st 8lbs to 10st 1lbs).
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds: a healthy BMI starts at 18.5 but extends only to 22.9. This is because these populations face higher risks of type 2 diabetes and cardiovascular disease at lower BMI levels.
Use our free weight converter to check what your height's healthy range is in your preferred units — stone, pounds, or kilograms.
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.
Why Weight Range Matters More Than a Single Number
A healthy weight range accounts for natural variation in bone density, muscle mass, and individual body composition. Two people at the same height and weight can have very different body fat percentages depending on how much they exercise and their genetics.
This is why BMI has limitations — it doesn't distinguish between muscle and fat. An athlete might have a high BMI but excellent health markers. Conversely, someone within the "healthy" BMI range might have poor cardiovascular fitness or metabolic health. The most complete picture includes your waist circumference (over 94cm for men or 80cm for women indicates increased health risk) alongside your weight and height.
Your GP can discuss your personal healthy weight range based on your full health picture, not just the NHS guidelines.
- 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.
How do I calculate my healthy weight range for my height?
Find your height in centimetres, then multiply it by itself, then multiply by 18.5 (lower bound) and 24.9 (upper bound). Divide the results by 1000 for kg. Our free BMI calculator above does this instantly — just enter your height and current weight to see exactly where you fall.
Is there a different healthy weight range for different ages?
BMI categories are the same for adults of all ages (over 18). However, older adults may lose muscle mass naturally, so your GP might discuss healthy weight differently depending on your age, fitness level, and medical history. Children use entirely different growth charts and centiles — never apply adult BMI to children.
What if I'm muscular — does BMI still apply to me?
BMI doesn't account for muscle mass, which is denser than fat. Athletes and very muscular individuals may have a high BMI despite low body fat. If you're very physically active, discuss your weight with your GP rather than relying solely on BMI. Waist circumference and body composition are better indicators in this case.
What weight should I aim for if I'm overweight?
Aim for a weight within the healthy BMI range (18.5–24.9) for your height — or use NHS lower thresholds if you're of South Asian or Black African heritage. However, even losing 5–10% of your current weight brings significant health benefits. Your GP can help set realistic, personalised targets based on your health conditions and circumstances.
Does my ethnicity affect what weight is healthy for me?
Yes. The NHS recommends lower BMI thresholds for South Asian, Chinese, Black African, and Black Caribbean adults because these groups face higher metabolic risks at lower BMI levels. If you're from these backgrounds, a healthy BMI range is 18.5–22.9 rather than 18.5–24.9. Always discuss this with your GP to understand what's healthy for you specifically.
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.