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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Appropriate Weight Calculator — What's a Healthy Weight for You?
Finding an appropriate weight for your body isn't just about a number on the scales — it's about understanding what range is healthy for your height, age, and overall health. The NHS uses body mass index (BMI) as the primary screening tool, alongside other measurements like waist circumference, to determine whether your current weight puts you at risk of weight-related health conditions. This guide explains how to calculate your appropriate weight range using evidence-based UK health guidance, and shows you how our free BMI calculator and weight converter can help you track where you sit within the healthy weight spectrum.
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 to Calculate Your Appropriate Weight Range
Your appropriate weight depends primarily on your height, age, and body composition — not just what you weigh. The NHS defines healthy weight using BMI (body mass index), which divides your weight in kilograms by your height in metres squared.
The healthy BMI range for most UK adults is 18.5 to 24.9. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a lower threshold of 18.5 to 22.9, as these groups face higher health risks at the same BMI.
To find your appropriate weight range:
- Calculate your current BMI using our free BMI calculator above
- If your BMI falls below 18.5, you may be underweight
- If it's between 18.5–24.9, you're in the healthy weight range
- If it's 25–29.9, you're classed as overweight
- If it's 30 or above, you're in the obese category
Our weight converter tool lets you switch between kg, stone, and pounds — useful for understanding what different weights mean in the measurements you're familiar with.
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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 Appropriate Weight Matters for Your Health
Maintaining an appropriate weight for your height reduces your risk of serious health conditions including type 2 diabetes, cardiovascular disease, certain cancers, sleep apnoea, and joint problems. Even a modest weight loss of 5–10% of your body weight can improve blood pressure, blood sugar control, and cholesterol levels.
However, BMI has limitations — it doesn't distinguish between muscle and fat, so athletes may have a high BMI despite low body fat. Your GP can provide personalised advice about what an appropriate weight means for your individual health. If you're considering weight management options, including prescription treatments like Mounjaro or Wegovy, our free GLP-1 weight loss calculator can help you understand potential outcomes alongside lifestyle changes.
- 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's the difference between appropriate weight and ideal weight?
Appropriate weight is a health-based range determined by your BMI and NHS guidelines. Ideal weight is more individual — it accounts for muscle mass, bone density, and personal health history. Your GP can help you define what's ideal for you specifically. BMI provides a screening tool, not a prescription for an exact number.
How do I calculate my appropriate weight range from my height alone?
Multiply your height in metres by itself, then multiply by 18.5 (lower bound) and 24.9 (upper bound). For example, at 1.73m tall, your appropriate range is roughly 55–74kg (8st 10lbs to 11st 10lbs). Use our free BMI calculator above for instant, personalised results.
Does age affect what an appropriate weight is?
Age can affect how your body distributes weight and your metabolic rate, but NHS BMI categories remain the same across adult ages. However, older adults may lose muscle naturally, so your GP's guidance becomes especially important. Muscle weighs more than fat, so strength training may increase weight while improving health.
Is an appropriate weight the same for men and women?
BMI categories are identical for men and women, but average muscle mass differs — men typically have more. So two people with the same BMI may look different. Body composition (muscle vs fat) matters more than weight alone. Our progress tracker helps you monitor changes beyond just the scales.
Can I use an appropriate weight calculator if I'm pregnant?
Standard BMI calculators aren't suitable during pregnancy, as weight gain is expected and necessary. The NHS provides separate guidance for healthy weight gain in pregnancy. Always discuss your weight with your midwife or GP during pregnancy rather than using online calculators.
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.