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
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Healthy Weight Charts by Age and Height
A healthy weight varies significantly based on your age, height, and individual body composition. Rather than a single "ideal" weight, the NHS recommends using your BMI (body mass index) and waist circumference to assess whether you're in a healthy weight range. This guide explains how weight relates to age and height, and provides you with practical tools to check your personal healthy weight using UK measurements and NHS guidance. Your GP can also provide personalised advice based on your individual health profile.
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 Healthy Weight Relates to Age and Height
Healthy weight depends primarily on height, not age. The NHS uses BMI (body mass index) as the main screening tool, which is calculated from your weight and height alone. A healthy BMI is 18.5 to 24.9 for most UK adults. For example, a person who is 1.73m (5ft 8in) tall has a healthy weight range of approximately 55–74 kg (8st 8lbs to 11st 8lbs), regardless of whether they are 25 or 65 years old.
However, age does affect metabolism, muscle mass, and how your body stores fat. Older adults may naturally experience some weight gain even with the same diet, due to reduced muscle mass and slower metabolism. Additionally, for people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower healthy BMI thresholds (18.5–22.9) because these groups face higher health risks at higher BMI levels.
Use our free BMI calculator above to find your personal healthy weight range based on your exact height and current weight. The weight converter tool can also help you switch between kilograms, stone, and pounds for easy reference.
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 Age Matters Less Than Height and Fitness
Whilst age itself isn't a direct factor in calculating healthy weight, it does influence the way your body manages weight. Muscle mass naturally declines with age—approximately 3–8% per decade after age 30—which reduces your resting metabolic rate and can make weight management more challenging. This is why older adults may need to be more active or adjust their diet to maintain the same weight.
Other factors that affect healthy weight beyond age and height include genetics, medical conditions (like thyroid disease or PCOS), medications, and lifestyle. Rather than comparing yourself to age-based averages, focus on your personal BMI range and how you feel physically. Our progress tracker can help you monitor changes over time and work towards your individual health goals, whilst the weight converter makes it easy to track your progress in your preferred UK measurements.
- 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 is the healthy weight for my height?
To find your healthy weight range, calculate your BMI using your height and weight. For most UK adults, a BMI of 18.5–24.9 is healthy. Use our free BMI calculator above to find your personal range instantly. Your GP can also provide personalised guidance based on your individual health.
Does my age affect what weight I should be?
Age itself doesn't change your healthy BMI range, which is based on height. However, age affects metabolism and muscle mass—older adults may need more physical activity to maintain weight. For personalised advice, speak to your GP.
How do I convert my weight to the right units for a weight chart?
Use our free weight converter to switch between kilograms, stone, and pounds instantly. Enter your weight and see the conversion immediately. The NHS uses kilograms clinically, but many UK adults prefer stone and pounds.
What if I'm not in the healthy weight range for my height?
If your BMI falls outside the healthy range, your GP can discuss weight management options with you. These might include dietary changes, physical activity, or—if appropriate—prescription weight management support through NHS services.
Are there different weight recommendations for different ethnic backgrounds?
Yes. The NHS recommends lower healthy BMI thresholds for people of South Asian, Chinese, Black African, or Black Caribbean heritage (18.5–22.9 instead of 18.5–24.9), because these groups face higher health risks at higher BMI levels. Your GP can discuss this with you.
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.