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
Age Chart For Weight And Height — UK Health Reference
Understanding healthy weight ranges for your age and height is an important part of weight management. In the UK, the NHS uses BMI (body mass index) as the primary screening tool for assessing healthy weight across all adult age groups. Unlike some health systems that adjust targets by age alone, UK health guidance focuses on BMI categories alongside age-related health conditions and individual circumstances. This guide explains how age, height, and weight interact, and how to assess what a healthy weight means for you using evidence-based NHS health advice.
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 Age Affects Healthy Weight Ranges
Age itself doesn't change your healthy BMI range — the NHS healthy weight categories remain consistent for all adults regardless of age. However, how weight affects your health does change with age. Younger adults may tolerate weight fluctuations better, whilst older adults face increased health risks from excess weight, particularly regarding cardiovascular disease, type 2 diabetes, and joint stress. Additionally, muscle mass naturally decreases with age (a process called sarcopenia), meaning the same weight at age 25 and age 65 may represent different body compositions. For this reason, older adults should pay particular attention to waist circumference alongside BMI, as abdominal fat carries greater health risk. Your GP can provide personalised guidance on what a healthy weight means specifically for your age, height, and individual health profile. Use our free BMI calculator above to check your current BMI instantly.
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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.
Healthy Weight Ranges By Height — UK Context
Rather than age-specific weight charts, the NHS recommends using BMI and waist circumference as the primary measures of healthy weight. For any given height, there is a healthy weight range that produces a BMI between 18.5 and 24.9. For example, an adult who is 5ft 8in (173cm) tall should aim for a weight between approximately 55kg (8st 10lbs) and 75kg (11st 11lbs) to maintain a healthy BMI. These ranges apply equally to 25-year-olds and 65-year-olds. However, adults of South Asian, Chinese, Black African, or Black Caribbean heritage have lower healthy BMI thresholds due to higher health risks at standard BMI ranges. Try our weight converter to switch between kg, stone, and pounds for your height.
- 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 healthy weight change as you get older?
No — the NHS BMI categories (18.5–24.9 for healthy weight) remain the same across all adult ages. However, excess weight carries greater health risk as you age, particularly for cardiovascular health and type 2 diabetes. Older adults should also monitor waist circumference, as abdominal fat increases health risks more significantly with age.
What is the healthy weight for a 40-year-old who is 5ft 6in tall?
For someone 5ft 6in (168cm) tall, a healthy BMI (18.5–24.9) corresponds to a weight between approximately 52kg (8st 3lbs) and 70kg (11st 0lbs). This range applies regardless of whether you are 40, 50, or 60 years old. Your GP can advise on a personally appropriate weight target based on your health conditions and medical history.
Is BMI accurate for older adults?
BMI is generally useful for older adults but has limitations. It doesn't distinguish muscle from fat — older adults naturally lose muscle mass with age, so the same BMI may represent different body compositions. Waist circumference is particularly important to measure alongside BMI for older adults, as belly fat carries greater cardiovascular risk.
How can I work out my healthy weight range for my height?
Use our free BMI calculator above to enter your height and current weight — it will instantly show you your BMI category and healthy weight range for your specific height. Alternatively, multiply your height in metres by itself, then multiply by 18.5 (lower healthy bound) and 24.9 (upper healthy bound) to calculate your personal range.
Do weight charts differ for men and women at the same age and height?
No — NHS healthy BMI categories are identical for men and women at the same height and age. However, women typically have higher body fat percentages at the same BMI than men due to biological differences. Your GP can discuss what a healthy weight means for you individually, taking into account your fitness level and muscle mass.
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.