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 According to Age, Height and Weight
There's no single "ideal" weight that applies to everyone of the same age and height — weight depends on factors like muscle mass, bone density, and individual health. However, the NHS provides evidence-based healthy weight ranges using BMI (body mass index) and your height, adjusted for age-related changes. These guidelines help you understand whether your current weight falls within a healthy range for your body, and whether weight management might benefit your health. Use our free BMI calculator above to check your personal range, or read on to understand how UK health guidance defines healthy weight.
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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 Guidance Defines Healthy Weight
The NHS uses BMI (body mass index) as the primary tool to assess healthy weight ranges. BMI is calculated by dividing your weight in kilograms by your height in metres squared. For most UK adults, a healthy BMI falls between 18.5 and 24.9. However, BMI changes with age and differs by ethnicity:
- Adults aged 18–64: Use standard NHS BMI categories (18.5–24.9 healthy)
- Adults over 65: A slightly higher BMI (around 25–27) may be healthier due to natural muscle loss with age
- South Asian, Chinese, Black African, or Black Caribbean adults: Lower thresholds apply (18.5–22.9 healthy) because these groups face higher disease risk at lower BMI levels
To convert your weight between kg, stone, and lbs, use our free weight converter on this page. Remember: BMI does not account for muscle mass, so athletes may have a high BMI but low body fat.
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.
Healthy Weight Ranges by Height (UK Examples)
Here are approximate healthy weight ranges (BMI 18.5–24.9) for common UK heights:
- 5ft 4in (163cm): Approximately 47–64 kg (7st 6lbs–10st 1lbs)
- 5ft 6in (168cm): Approximately 52–70 kg (8st 2lbs–11st 0lbs)
- 5ft 8in (173cm): Approximately 55–74 kg (8st 8lbs–11st 10lbs)
- 5ft 10in (178cm): Approximately 59–80 kg (9st 4lbs–12st 8lbs)
These are general ranges only. Your GP or a healthcare professional can provide personalised advice based on your individual health, fitness level, and medical history. If you're concerned about your weight, speak to your GP about what a healthy range means for you specifically.
- 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 with age?
Yes, slightly. Muscle naturally decreases with age, so older adults (65+) may have a slightly higher healthy BMI (25–27) compared to younger adults (18.5–24.9). Bone density and metabolism also change with age. Your GP can advise on what's healthy for your specific age and circumstances.
Why do South Asian and Black African adults have different healthy weight ranges?
Research shows that South Asian, Chinese, Black African, and Black Caribbean populations develop type 2 diabetes and heart disease at lower BMI levels than European populations. The NHS adjusted its guidelines for these groups to reflect their actual health risk profiles, starting healthier weight categories at BMI 18.5–22.9 instead of 18.5–24.9.
What if my BMI is healthy but I feel overweight?
BMI is a screening tool but has limits — it doesn't distinguish between muscle and fat. If your BMI is healthy but you have concerns about your weight or health, speak to your GP. They can assess your body composition, waist circumference, and overall health rather than relying on BMI alone.
How can I find my exact healthy weight range?
Use our free BMI calculator above to enter your height and current weight — it will show you the healthy BMI range (18.5–24.9) for your height in kg, stone, and lbs. For personalised guidance, your GP can advise on what's healthy for your specific age, health conditions, and lifestyle.
Is weight management only about age and height?
No. Healthy weight depends on many factors including age, height, muscle mass, bone density, genetics, medical conditions, and overall fitness. The NHS uses age-adjusted BMI as a starting point, but your GP can discuss what weight management means for your individual health goals and circumstances.
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.