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 for Ladies: What You Need to Know
BMI (Body Mass Index) is a health screening tool that helps measure whether your weight is healthy for your height. For women in the UK, understanding your BMI range is an important first step in assessing your overall health. The NHS uses BMI categories to help identify potential health risks, though it's worth knowing that BMI has limitations and is just one part of a fuller health picture. Use our free BMI calculator above to find your personal BMI instantly, and discover where you fall on the NHS health scale.
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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 and Healthy Ranges for Women
The NHS BMI categories apply equally to women and men, though it's important to remember that BMI doesn't distinguish between muscle and fat. According to NHS guidelines, the healthy BMI range for women is 18.5 to 24.9. If your BMI falls below 18.5, you're in the underweight category; between 25.0 and 29.9 is overweight; 30.0 to 34.9 is obese (Class I); and 35.0 to 39.9 is obese (Class II). A BMI of 40.0 or above is classified as severely obese (Class III).
For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds. Your healthy weight range would be BMI 18.5 to 22.9, as these groups face higher risks of type 2 diabetes and heart disease at lower BMI levels. You can use the standard BMI formula — weight (kg) divided by height (m) squared — or simply use our BMI calculator above to find your exact number 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.
BMI Limitations and What Else Matters for Women's Health
While BMI is a useful screening tool, it has important limitations. BMI doesn't account for muscle mass, so very fit women with strong muscles may have a higher BMI without being unhealthy. It also doesn't measure where fat is stored on your body — waist circumference is equally important. The NHS recommends women measure their waist: over 80cm (31.5 inches) suggests increased health risk, and over 88cm (34.5 inches) suggests high risk.
For a more complete picture of your health, consider using our free weight converter to track changes over time, and combine BMI assessment with regular GP check-ups. Your GP can discuss your individual health context, family history, and any weight-related health conditions to give you personalised guidance beyond what any number alone can show.
- 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 ideal BMI for women in the UK?
The NHS defines a healthy BMI range for women as 18.5 to 24.9. However, for women of South Asian, Chinese, Black African, or Black Caribbean heritage, the healthy range is 18.5 to 22.9 due to higher health risks at higher BMI levels. Your GP can advise on your personal ideal range.
How do I calculate my BMI if I'm a woman?
Divide your weight in kilograms by your height in metres squared. For example, if you weigh 65kg and are 1.65m tall: 65 ÷ (1.65 × 1.65) = BMI 23.9. Our free BMI calculator does this instantly — just enter your weight and height above.
Is BMI accurate for women with muscle?
BMI has limitations and doesn't distinguish between muscle and fat. A very fit woman with strong muscles may have a higher BMI but be perfectly healthy. That's why your GP may also assess waist circumference, fitness level, and overall health rather than relying on BMI alone.
What does a BMI of 25-29.9 mean for women?
A BMI in the 25.0 to 29.9 range is classified as overweight according to NHS guidelines. While not yet in the obese category, the NHS recommends considering lifestyle changes such as balanced diet and physical activity to reduce health risks associated with excess weight.
How is BMI different for women of different ethnic backgrounds?
The NHS recommends lower BMI thresholds for women of South Asian, Chinese, Black African, and Black Caribbean heritage because these groups have higher risks of type 2 diabetes and cardiovascular disease at the same BMI levels as white women. Your GP can advise on thresholds relevant to your background.
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.