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 Your Ideal Weight By Age And Height?
Your ideal weight depends primarily on your height, not your age. The NHS defines a healthy weight range using BMI (body mass index) of 18.5 to 24.9, which applies equally to adults of all ages. However, factors like muscle mass, bone density, and individual health conditions mean "ideal weight" varies between people. This guide explains how to find your healthy weight range for your specific height using the NHS BMI framework, and why age-specific weight tables are less reliable than personalised assessment.
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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.
Healthy Weight Range By Height — BMI Based
The easiest way to find your ideal weight range is to use your height and the healthy BMI range of 18.5–24.9. Here are common healthy weight ranges for UK adults at different heights:
- 5ft 2in (157cm): 45–61 kg (7st–9st 8lbs)
- 5ft 4in (163cm): 49–66 kg (7st 9lbs–10st 5lbs)
- 5ft 6in (168cm): 54–72 kg (8st 6lbs–11st 5lbs)
- 5ft 8in (173cm): 55–76 kg (8st 8lbs–12st)
- 5ft 10in (178cm): 59–82 kg (9st 3lbs–12st 13lbs)
- 6ft (183cm): 64–87 kg (10st 1lb–13st 9lbs)
These ranges assume a BMI of exactly 18.5 (lower healthy limit) and 24.9 (upper healthy limit). Your GP or a healthcare professional can help you understand where within this range is best for your individual health. Use our free BMI calculator above to find your exact healthy weight range for your height 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.
Why Age Alone Isn't The Answer
You may have seen "ideal weight by age" charts online, but age is not a reliable indicator of healthy weight. A healthy weight depends almost entirely on height and body composition, not age. A 25-year-old and a 65-year-old who are the same height have the same healthy BMI range (18.5–24.9). What does change with age is muscle mass — older adults naturally lose muscle and may need to maintain slightly higher protein intake to preserve strength. The NHS healthy weight calculator uses only height and weight, not age, because BMI science shows this is more accurate. Try our free weight converter and BMI calculator above to find your personalised healthy weight range right now.
- 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 ideal weight different for men and women?
No — the healthy BMI range of 18.5–24.9 is the same for all adults regardless of sex. However, women and men naturally have different body fat percentages at the same BMI due to hormones and muscle distribution. Your GP can discuss what healthy weight means for your individual health.
Does my ideal weight change as I get older?
The healthy BMI range stays the same throughout adulthood (18.5–24.9). However, as you age, maintaining muscle becomes more important for strength and mobility. A GP can provide personalised advice about weight, fitness, and health as you age.
What if I'm outside the healthy weight range?
If your BMI is above 24.9, your GP can discuss gradual, sustainable weight loss. If below 18.5, discuss nutrition and health. The NHS recommends losing weight at 0.5–1 kg per week. Our GLP-1 weight loss calculator can help estimate potential progress with medical support.
Are there ethnic differences in ideal weight?
Yes — the NHS recommends lower BMI thresholds for people of South Asian, Chinese, Black African, and Black Caribbean heritage due to higher health risks at the same BMI. A healthy BMI for these groups starts at 18.5–22.9 instead of 18.5–24.9. Discuss your personal range with your GP.
How do I calculate my exact ideal weight range?
Use the free BMI calculator above — enter your height and it will show your healthy weight range. Or use this formula: healthy weight = your height in metres squared × 18.5 (lower limit) and × 24.9 (upper limit). Our calculator handles this instantly. ```
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.