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 Weight Chart — What's a Healthy Weight for Your Age?
There isn't a single "ideal" weight based purely on age — healthy weight depends far more on your height, body composition, and individual health profile. However, age does play a role in weight management, as metabolism naturally changes over time and muscle mass typically declines. This guide explains how to find your healthy weight range at any age using NHS-backed health metrics, and how tools like BMI calculators and weight converters can help you understand your current weight in the context of 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.
Why Age Alone Doesn't Determine Healthy Weight
Age is just one factor in weight health — it's not the primary determinant. The NHS prioritises height and BMI over age when assessing healthy weight ranges. Two people aged 50 might need very different weights depending on how tall they are and their muscle mass. What does change with age is metabolism and activity level. Basal metabolic rate (the energy you burn at rest) typically decreases by about 2–8% per decade after age 30. Muscle mass also declines naturally with age, which affects calorie requirements. Additionally, certain age-related health conditions like type 2 diabetes, high blood pressure, and joint problems become more common with increasing weight — making weight management increasingly important in middle and older age.
- Metabolism slows with age, requiring fewer calories
- Muscle mass declines naturally — strength training helps offset this
- Age-related health risks increase with excess weight
- Individual variation is huge — focus on your personal BMI range instead
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.
Finding Your Healthy Weight Range at Any Age
The best way to find your healthy weight range is using the NHS BMI categories, which apply equally to all adults regardless of age. A healthy BMI is 18.5 to 24.9 for most adults; for South Asian, Chinese, Black African, or Black Caribbean adults, the range is 18.5 to 22.9. To calculate your personal healthy weight range, multiply your height in metres squared by 18.5 (lower bound) and 24.9 (upper bound). For example, an adult who is 1.75m tall has a healthy weight range of approximately 56–76 kg (8st 12lbs to 12st 0lbs). Use our free BMI calculator above to check your personal BMI instantly, or our weight converter to switch between kg, stone, and pounds. Your GP can also provide personalised guidance for your specific age and health profile.
- 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 different healthy weight chart for older adults?
No — NHS BMI categories remain the same throughout adulthood (18.5–24.9 is healthy). However, some research suggests very elderly people (80+) may have slightly different optimal ranges. Always discuss your personal healthy weight with your GP, especially if you have age-related health conditions or take multiple medications.
Does metabolism really slow down as you age?
Yes, basal metabolic rate decreases approximately 2–8% per decade after age 30, meaning you need fewer calories to maintain the same weight. This is partly due to muscle loss. Strength training and adequate protein can help preserve muscle mass and support weight management as you age.
What's the best weight loss approach for older adults?
The NHS recommends sustainable loss of 0.5–1 kg per week for all ages. For older adults, this is particularly important because gradual weight management can result in muscle loss, which is already declining naturally. A balanced diet, strength training, and gradual calorie deficit are ideal. Always consult your GP before starting weight loss.
Should I use a different BMI chart if I'm over 65?
Standard NHS BMI categories apply to all adults, including those over 65. However, BMI has limitations — it doesn't account for muscle mass or bone density, which change with age. Your GP can assess your weight health in the context of your overall health profile, medications, and mobility.
Can I use an age-weight chart from the internet to check if I'm healthy?
Most generic "age weight charts" online are not evidence-based and often reflect average weights rather than healthy weights. Use the NHS BMI calculator and healthy weight ranges instead — these are based on health risk data. Our free BMI calculator above provides instant, NHS-aligned assessment for your personal height and weight.
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.