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 A Healthy Weight For Your Height And Age?
There isn't a single "correct" weight for your height and age — healthy weight varies significantly based on muscle mass, frame size, and individual health factors. However, the NHS provides guidance on healthy weight ranges using BMI (Body Mass Index), which applies to adults aged 18 and over. Your GP can give you personalized advice about what weight is healthy for you specifically, taking into account your medical history and individual circumstances. Age itself doesn't change healthy weight ranges, but certain conditions more common in older age may affect what's appropriate 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.
NHS Healthy Weight Ranges By Height
The most practical way to find your healthy weight range is to use BMI guidelines. The NHS defines a healthy BMI as 18.5 to 24.9 for most adults. This translates to specific weight ranges depending on your height. For example, at 1.70m (5ft 7in), a healthy weight range is approximately 53–72 kg (8st 5lbs to 11st 4lbs). At 1.80m (5ft 11in), the range is 60–81 kg (9st 6lbs to 12st 10lbs).
If you're 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, as these populations face higher health risks at the same weight. You can calculate your exact healthy weight range instantly using our free BMI calculator above, which gives you personalized results based on your height.
- Healthy BMI: 18.5–24.9
- South Asian/Chinese/Black African/Caribbean healthy BMI: 18.5–22.9
- Age doesn't change BMI categories — they apply equally to adults aged 20–80
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 BMI Matters — And What It Doesn't Tell You
BMI is a useful screening tool but has important limitations. It doesn't distinguish between muscle and fat — an athletic person with high muscle mass may have a "high" BMI but excellent health. BMI also doesn't account for where fat is stored. Waist circumference matters: the NHS advises that men with waist over 94cm (37in) and women over 80cm (31.5in) have increased health risk, regardless of BMI.
For a complete picture of your health, consider using our free weight converter to understand your weight in different units, then discuss the results with your GP. They can assess your individual health markers — blood pressure, cholesterol, blood sugar — which matter far more than a number on the scales. Your GP can also advise whether you need support with weight management through NHS services or lifestyle changes.
- 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 age affect what weight is healthy for me?
Age doesn't change BMI categories — the healthy BMI range (18.5–24.9) applies to all adults aged 18 and over. However, older adults may lose muscle naturally, so your GP might discuss your individual health profile rather than just BMI. Other health factors like blood pressure and cholesterol become increasingly important with age.
What's the difference between a "healthy weight range" and an "ideal weight"?
A healthy weight range is based on BMI and gives you a safe band of weights for your height. Your ideal weight within that range depends on muscle mass, frame size, and personal health goals. There's no single perfect number — anywhere within your healthy range is appropriate for you.
Can I use the same healthy weight range as my friend if we're the same height?
Not necessarily. Two people of identical height may have different healthy weight ranges due to muscle mass, bone density, and frame size. Use our BMI calculator with your own height and weight to find your personal range. Your GP can also provide personalized guidance.
Is my weight healthy if I feel good and have no health problems?
How you feel isn't always a reliable indicator of health — some people with excess weight have no symptoms initially. It's worth checking your BMI and discussing your results with your GP. They can assess blood pressure, cholesterol, and blood sugar, which are more predictive of future health than how you feel now.
How do I know if I need support with weight management?
If your BMI is 30 or above, or 27–29 with weight-related health conditions (diabetes, high blood pressure, heart disease), discuss weight management options with your GP. The NHS offers free support through tier 1 and 2 services (self-help programmes and behaviour change), and specialist tier 3 services for more intensive support.
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.