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
BMI Levels for Women — What You Need to Know
BMI (Body Mass Index) levels for women follow the same NHS categories as men, but it's important to understand what your personal BMI means for your health. This guide explains the female BMI range, how to calculate yours, and the NHS thresholds that apply to you. Use our free BMI calculator above to find your exact BMI instantly.
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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.
Understanding Female BMI Categories and Healthy Ranges
The NHS BMI categories are the same for all adults, regardless of sex. Your BMI formula is simple: weight (kg) divided by height (metres) squared. A healthy BMI range for women is 18.5 to 24.9, which applies to most adult women in the UK.
- 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: BMI 40.0 and above
For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS BMI categories UK are adjusted lower due to higher health risks at standard BMI levels. The healthy range becomes 18.5–22.9, and overweight threshold starts at 23.0. Calculate your BMI using the calculator on this page to see exactly where you fall.
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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.
BMI Limitations and Complementary Health Measures
BMI limitations are important to understand. BMI does not distinguish between muscle and fat—athletes or women with high muscle mass may have a higher BMI but lower body fat. BMI also doesn't account for where fat is stored on your body. A healthy BMI is a useful screening tool, but it's only part of the picture.
The NHS recommends using waist circumference alongside BMI for a fuller assessment. For women, a waist measurement above 80cm (31.5 inches) indicates increased health risk; above 88cm (34.5 inches) indicates high risk. Age, fitness level, and medical history also matter. Your GP can provide personalised guidance on what your BMI means for your individual health.
- 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 healthy BMI range for women in the UK?
According to NHS guidelines, the healthy BMI range for all women is 18.5 to 24.9. If you're of South Asian, Chinese, Black African, or Black Caribbean heritage, the healthy range is 18.5 to 22.9 due to higher cardiovascular risk at higher BMI levels. Use our free BMI calculator to find your exact number.
How do I calculate my BMI as a woman?
The BMI formula is the same for everyone: weight in kg divided by height in metres squared. For example, if you weigh 65kg and are 1.65m tall, your BMI is 65 ÷ (1.65 × 1.65) = 23.9 (healthy weight). Our BMI calculator does this instantly—just enter your measurements above.
Is BMI accurate for women with muscle or athletic build?
No, BMI has limitations. It doesn't distinguish between muscle and fat, so athletic women with high muscle mass may have a higher BMI but lower body fat. For a complete picture, combine BMI with waist circumference measurement and speak to your GP about your individual health.
What BMI should women aim for?
The NHS healthy BMI range is 18.5–24.9 for most women (18.5–22.9 for South Asian and some other ethnic groups). However, "ideal" BMI varies based on age, muscle mass, and individual health. Your GP can advise what's healthy for you personally rather than aiming for a specific number.
Does BMI change with age for women?
BMI is calculated the same way regardless of age, but health risks at the same BMI may increase with age due to changes in muscle mass and metabolism. Older women may benefit from slightly higher BMI for better health outcomes. Your GP can give age-specific guidance based on your individual 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.