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 Is a Healthy Weight for Your Height and Age?
Your healthy weight depends primarily on your height rather than your age, and is measured using BMI (body mass index). According to NHS guidelines, a healthy BMI for most UK adults is between 18.5 and 24.9 — regardless of whether you're 25 or 65. However, age can affect how your body composition changes, and ethnicity influences the thresholds slightly. This guide explains how to find your healthy weight range and why BMI context matters for your personal health.
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.
BMI-Based Healthy Weight Ranges for Different Heights
Your healthy weight range is calculated based on your height using the BMI formula. For any given height, there's a specific weight band that falls within the healthy BMI range of 18.5–24.9.
For example, at 5ft 6in (168cm), a healthy weight range is approximately 52–69kg (8st 3lbs–10st 13lbs). At 5ft 10in (178cm), it's roughly 56–78kg (8st 12lbs–12st 4lbs). At 6ft (183cm), the healthy range is 55–82kg (8st 9lbs–12st 13lbs).
Important context: These ranges assume an average adult body composition. If you're very muscular, your BMI may be higher but your health risk may be lower. Conversely, if you have lower muscle mass, your actual health risk may differ from your BMI suggests. This is why your GP can give personalised guidance beyond BMI alone.
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds: a healthy BMI is 18.5–22.9, which means your healthy weight range will be narrower than the standard categories. Discuss this with your GP if relevant to you.
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 the BMI Calculator to Find Your Healthy Weight
Rather than calculating manually, use our free BMI calculator above to enter your exact height and current weight — it will instantly show you where you fall on the NHS BMI scale and your corresponding healthy weight range.
The calculator also shows the specific weight you'd need to reach to move from overweight into the healthy range, or from obese into overweight — giving you a practical target. Age doesn't change your healthy BMI range, but it may influence how quickly you can safely lose weight (your GP can advise). Once you know your target range, you can track progress using our free weight converter to switch between kg, stone, and pounds, or log your journey with our progress tracker as you work towards your healthy weight goals.
- 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 change what counts as a healthy weight?
No. The NHS BMI categories (healthy weight, overweight, obese) are the same for all adults regardless of age. A BMI of 22 is healthy whether you're 30 or 70. However, age may affect body composition — older adults often have less muscle mass — so your GP may consider factors beyond BMI alone when advising on your personal health.
Is healthy weight different for men and women?
The BMI formula and NHS categories are the same for all adults regardless of sex. However, average body composition does differ — women typically have higher body fat percentage at the same BMI than men. Individual healthy weight depends on height, not sex, though your GP may discuss personalised targets with you.
What if my height is between two values in the weight chart?
Use our BMI calculator for precise results. Enter your exact height in cm or feet/inches, and the calculator will show your personalised healthy weight range. This is more accurate than rounding to the nearest chart value.
Can I be healthy at a weight outside the BMI range?
The NHS BMI range (18.5–24.9) is a population-level guideline. Some muscular individuals may have a higher BMI but good health markers. Your GP can assess your overall health — including blood pressure, cholesterol, fitness, and waist circumference — to give you personalised advice beyond BMI alone.
How do ethnicity adjustments affect my healthy weight?
For South Asian, Chinese, Black African, and Black Caribbean adults, the NHS recommends a healthy BMI of 18.5–22.9 (narrower than the standard 18.5–24.9). This reflects higher health risk at lower BMI in these populations. Use your ethnicity context when checking your BMI category, or discuss with your GP.
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.