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 Proper Weight According to Height and Age?
There's no single "proper" weight that applies to everyone at the same height and age — but there are healthy weight ranges based on NHS guidance and BMI standards. Your ideal weight depends on your height, age, sex, muscle mass, and overall health. The best way to find your personal healthy weight range is using your BMI (body mass index) and consulting your GP. Start by using our free BMI calculator above to see where you fall on the NHS health scale, then use our weight converter to check your weight in stone, pounds, and kilograms.
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.
How NHS Defines Healthy Weight by Height
The NHS uses BMI (body mass index) as the primary tool to determine healthy weight ranges. A healthy BMI falls between 18.5 and 24.9 for most UK adults. Your BMI is calculated by dividing your weight in kilograms by your height in metres squared.
For any given height, there is a range of healthy weights, not a single target. For example, an adult who is 1.73m tall (5ft 8in) has a healthy weight range of approximately 55kg to 75kg (8st 10lbs to 11st 10lbs). However, BMI has limitations — it doesn't account for muscle mass, bone density, or where fat is stored on your body. Athletes may have a high BMI but low body fat.
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends slightly lower thresholds because these groups face higher health risks at the same BMI level. Your GP can provide personalised UK health guidance based on your individual circumstances.
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.
Factors That Affect Your Proper Weight Beyond Height and Age
Biological sex, muscle mass, bone density, genetics, and overall fitness level all influence what weight is healthy for you. Age does matter — muscle naturally decreases with age and metabolism may slow, so weight management becomes more important in later life. However, age alone is not used to calculate ideal weight.
Pregnancy, medications, medical conditions (like thyroid disease or PCOS), and lifestyle factors also play significant roles. Rather than chasing a single number, focus on maintaining a healthy BMI range and measuring your waist circumference — the NHS recommends waist measurements of under 94cm for men and under 80cm for women as an additional health marker. Use our weight converter and BMI calculator to track your progress, and speak to your GP if you're concerned about your weight in relation to your health.
- 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's the healthy weight range for my height?
Use our free BMI calculator above — enter your height and weight to find your healthy range instantly. For any height, a BMI of 18.5 to 24.9 is considered healthy by the NHS. Your GP can also provide personalised guidance based on your individual health factors.
Does age affect what weight is proper for me?
Age doesn't directly determine ideal weight, but it does matter for health. Muscle mass naturally decreases with age, so weight management becomes increasingly important for older adults. Your GP can advise on healthy weight targets specific to your age and health status.
Is BMI the only way to measure if my weight is healthy?
BMI is useful but has limitations — it doesn't distinguish between muscle and fat. The NHS also recommends measuring waist circumference (under 94cm for men, under 80cm for women) as an additional health indicator. Your GP can assess your overall health picture.
How do I find my healthy weight range if I'm South Asian, Chinese, Black African, or Black Caribbean?
The NHS recommends lower BMI thresholds for these groups due to higher health risks at the same BMI level. A healthy BMI for these populations is 18.5 to 22.9. Use our free BMI calculator above — it will show you the appropriate range for your heritage.
What if my weight is outside the healthy range — what should I do?
If your weight is above the healthy range, even a 5–10% reduction can improve your health significantly. Speak to your GP about weight management options. If you're interested in prescription weight loss support, your GP can refer you to specialist services or discuss options including GLP-1 medications.
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.