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 Is a Suitable Weight for You?
A suitable weight is different for everyone—it depends on your height, age, sex, and overall health rather than a single target number. In the UK, the NHS uses BMI (body mass index) to define healthy weight ranges, and recommends a BMI between 18.5 and 24.9 for most adults. However, suitable weight is also about how you feel, your energy levels, and your ability to manage weight-related health conditions. Our free BMI calculator above can help you find whether your current weight falls within the healthy range for your height, and the weight converter makes it easy to understand your weight in stone, pounds, or kilograms.
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 Find Your Suitable Weight Range
Your suitable weight range is based on your height and sex. The NHS uses BMI to define this range, which applies to adults aged 18 and over. For most adults, a healthy weight gives a BMI of 18.5 to 24.9. To calculate the healthy weight range for your height, multiply your height in metres by itself, then multiply the result by 18.5 and 24.9.
For example, if you are 5ft 8in (1.73m) tall, your healthy weight range is approximately 55 to 75 kg (8st 10lbs to 11st 10lbs). However, if you are of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds—a healthy BMI starts at 18.5 but should not exceed 22.9 for optimal health outcomes. Your GP can give you personalised advice about what a suitable weight means for your individual health and circumstances, especially if you have any weight-related health conditions.
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.
Beyond BMI — What Makes Weight Suitable?
BMI is a useful screening tool, but a suitable weight is about more than just a number. Waist circumference matters too—the NHS recommends keeping waist measurement below 94cm (37 inches) for men and 80cm (31.5 inches) for women. Even at a healthy BMI, carrying excess weight around the abdomen increases health risk. Your suitable weight should also allow you to feel energetic, manage any existing health conditions like type 2 diabetes or high blood pressure, and maintain activities you enjoy. If you're working towards a suitable weight, use our free progress tracker to log your journey, and remember that sustainable weight loss is typically 0.5 to 1 kg per week—slow, steady changes are more likely to last.
- 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 is the difference between suitable weight and ideal weight?
Suitable weight is a healthy range based on your height and BMI—typically 18.5 to 24.9 BMI. Ideal weight is a personal goal that may vary. Your suitable weight according to NHS guidelines is the medically recommended range; your ideal weight is what feels right for you within or near that range. Both matter for overall health and wellbeing.
Does suitable weight change with age?
BMI categories remain the same for adults aged 18 and over, so the BMI-based suitable weight range doesn't officially change. However, as you age, muscle naturally decreases and metabolism can slow, so maintaining a suitable weight may require adjustments to diet and activity. Your GP can advise on age-specific health targets.
How do I convert my suitable weight to stone?
Use our free weight converter at the top of this page to instantly convert kilograms to stone and pounds. For example, 70kg converts to 11 stone 0.1 lbs. Simply enter your weight and the tool will show you the conversion in all UK measurements.
Is there a suitable weight range if I have type 2 diabetes?
Yes. For adults with type 2 diabetes, a suitable weight is still defined by BMI (18.5–24.9), but even a 5–10% reduction in current weight can significantly improve blood sugar control and reduce medication needs. Your GP or diabetes nurse can help set a realistic suitable weight target for your individual situation.
Can I use a BMI calculator to find my suitable weight range?
Yes. Our free BMI calculator on this page instantly calculates your BMI and tells you whether your current weight falls into the healthy, overweight, or obese category. It also shows your healthy weight range for your height, making it easy to see what a suitable weight looks like for you.
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.