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 the Healthy BMI Range for Women?
A healthy BMI range for adult women in the UK is between 18.5 and 24.9, according to NHS guidelines. Your BMI (Body Mass Index) is calculated from your height and weight, and it gives a simple screening measure of whether you're at a healthy weight for your height. However, BMI is just one part of the health picture — other factors like where you carry weight, muscle mass, and overall fitness also matter. Understanding your BMI category helps you identify whether lifestyle changes or conversations with your GP might be helpful for your health.
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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.
NHS BMI Categories for Women
The NHS BMI categories apply equally to women and men. Your BMI is calculated using the formula: weight (kg) ÷ height (m)². The standard healthy BMI range for adult women is 18.5 to 24.9. Below this range is underweight (BMI below 18.5), and above 25.0 you enter the overweight category.
- Underweight: BMI below 18.5
- Healthy weight: BMI 18.5–24.9
- Overweight: BMI 25.0–29.9
- Obese (Class I): BMI 30.0–34.9
- Obese (Class II): BMI 35.0–39.9
- Severely obese (Class III): BMI 40.0+
Use our free BMI calculator above to find your personal BMI instantly based on your height and weight in stone, pounds, or kilograms.
Clinically BackedWeight Loss
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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.
Important BMI Limitations and Health Context
While BMI is a useful screening tool, it has significant limitations. BMI does not distinguish between muscle and fat — athletes or women with high muscle mass may have a higher BMI but lower body fat percentage. BMI also doesn't account for where fat is stored; excess weight around the stomach carries greater health risk than fat stored elsewhere. For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds: a healthy range of 18.5–22.9 rather than 18.5–24.9, as these groups face higher cardiovascular and diabetes risk at the same BMI.
Your GP can assess your individual health and discuss whether your weight is right for you, considering your fitness, family history, and any health conditions.
- 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 BMI should a woman aim for?
The NHS recommends a healthy BMI range of 18.5–24.9 for adult women. However, this is a screening tool only — some women are healthier at the lower end, others at the higher end, depending on muscle mass and individual health. Your GP can advise what's right for you personally.
Is BMI different for women than men?
No, the BMI formula and categories are the same for women and men. However, women typically have a higher natural body fat percentage than men, so some experts suggest slightly different body composition targets — but NHS BMI ranges apply to all adults equally.
What if I'm a woman of South Asian heritage — is my BMI range different?
Yes. The NHS recommends lower thresholds for women of South Asian, Chinese, Black African, or Black Caribbean heritage: a healthy BMI of 18.5–22.9 (not 18.5–24.9). These groups have higher risk of type 2 diabetes and heart disease at the same BMI, so earlier intervention may be beneficial.
How do I calculate my BMI?
BMI = weight (kg) ÷ height (m)². For example, if you weigh 65kg and are 1.65m tall: 65 ÷ (1.65 × 1.65) = BMI of 23.9. Our BMI calculator above does this instantly — just enter your height and weight in stone, pounds, or kilograms.
What should I do if my BMI is outside the healthy range?
If your BMI is above 25 or below 18.5, consider speaking with your GP. They can assess your individual health, discuss whether weight change is appropriate, and suggest evidence-based approaches like dietary changes, increased physical activity, or referral to weight management support services if needed.
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.