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 Suggested Weight for Your Height?
There's no single "ideal" weight — it varies based on age, muscle mass, bone density, and individual health factors. However, the NHS provides a healthy weight range for each height, based on BMI (body mass index). Use our free BMI calculator to find where your current weight sits, and discover the healthy weight range for your specific height using evidence-based UK health guidance.
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.
Understanding Healthy Weight Ranges by Height
The NHS uses BMI to define healthy weight ranges, which fall between 18.5 and 24.9 for most UK adults. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the healthy range is 18.5 to 22.9 due to higher health risks at higher BMI levels. Your healthy weight depends on your height — taller individuals naturally weigh more at the same BMI.
Example healthy weight ranges:
- At 5ft 4in (163cm): approximately 50–63kg (7st 12lbs to 10st)
- At 5ft 7in (170cm): approximately 54–72kg (8st 6lbs to 11st 4lbs)
- At 5ft 10in (178cm): approximately 58–77kg (9st 1lb to 12st 1lb)
- At 6ft (183cm): approximately 63–83kg (10st to 13st)
These are approximate ranges — your GP can provide personalised guidance based on your health history. Use our weight converter above to switch between kg, stone, and lbs instantly.
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.
BMI Limitations and What Else Matters
BMI is a useful screening tool but has important limitations. It doesn't distinguish between muscle and fat — athletes may have a high BMI but low body fat. BMI also doesn't account for where fat is stored. The NHS recommends checking waist circumference alongside BMI: men should aim for under 94cm (37in), women under 80cm (31.5in).
Age, fitness level, and overall health are equally important. Someone at the upper end of a healthy BMI range who exercises regularly may be healthier than someone at the lower end with poor fitness. Your GP can assess whether your current weight is appropriate for your individual circumstances and health goals. Calculate your personal BMI now using the calculator on this page.
- 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.
Is there a standard "ideal weight" chart for UK adults?
The NHS doesn't publish a single ideal weight — it provides healthy BMI ranges instead. A healthy BMI is 18.5–24.9 for most adults, or 18.5–22.9 for people of South Asian, Chinese, Black African, or Black Caribbean heritage. Within each BMI range, there's a healthy weight zone depending on your height. Your GP can advise if your current weight is healthy for you personally.
How do I calculate my healthy weight range from my height?
Use the BMI formula: multiply the lower BMI limit (18.5) by your height in metres squared, then repeat for the upper limit (24.9). For example, at 1.70m tall: lower = 18.5 × 1.70² = 53.4kg; upper = 24.9 × 1.70² = 71.9kg. Our free BMI calculator above does this instantly — just enter your height and it shows your healthy weight range.
Should I aim for the lower or upper end of my healthy weight range?
There's no universal answer — it depends on your muscle mass, bone density, and personal health factors. Someone with significant muscle may naturally sit toward the upper end. Your fitness level, energy, and health markers (blood pressure, cholesterol) matter more than hitting a specific number. Discuss your ideal weight target with your GP rather than aiming for an arbitrary figure.
Does healthy weight change with age?
BMI categories remain the same regardless of age, but how weight is distributed changes. Older adults often lose muscle mass naturally, so a weight that seemed high in your 30s might be appropriate in your 70s. Muscle weighs more than fat, so two people of the same age and height can have very different healthy weights. Your GP can advise what's right for your age and health status.
Why are the healthy weight ranges different for people from certain ethnic backgrounds?
Research shows that people of South Asian, Chinese, Black African, and Black Caribbean heritage have a higher risk of type 2 diabetes and heart disease at the same BMI as other groups. The NHS therefore recommends lower BMI thresholds (18.5–22.9 instead of 18.5–24.9) for these populations. This reflects evidence-based health risk, not appearance or fitness — it's personalised UK health guidance.
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.