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 the Normal BMI Range for Women?
The normal or healthy BMI range for women in the UK is 18.5 to 24.9, according to NHS guidelines. This applies to most adult women regardless of age. However, if you're of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a slightly lower healthy range of 18.5 to 22.9. Your personal BMI depends on your height and weight. Use our free BMI calculator above to find your exact BMI instantly, or read on to understand what these ranges mean 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 and Healthy Weight Ranges
The NHS BMI categories for women (and all adults) are:
- Below 18.5: Underweight
- 18.5–24.9: Healthy weight (normal range)
- 25.0–29.9: Overweight
- 30.0–34.9: Obese (Class I)
- 35.0–39.9: Obese (Class II)
- 40.0+: Severely obese (Class III)
To calculate your BMI formula, divide your weight in kilograms by your height in metres squared. For example, a woman who is 1.65m tall and weighs 60kg has a BMI of 22.1 — well within the healthy range. The healthy BMI threshold of 24.9 is not arbitrary; it's based on statistical evidence showing increased health risks above this point. You can instantly calculate your personal BMI using our free tool on this page.
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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 to Consider
While BMI is useful for screening, it has important BMI limitations. BMI does not distinguish between muscle and fat, so athletic women with high muscle mass may have a high BMI but low body fat. Age, bone density, and body composition also affect health risk independent of BMI. The NHS recommends measuring waist circumference alongside BMI: a healthy waist circumference for women is under 80cm (31.5 inches). Excess weight around the abdomen carries higher health risks than weight distributed elsewhere. Your GP can provide personalised advice about what your individual BMI means for your health, particularly if you have existing health conditions or family history of weight-related illness.
- 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 is normal for a woman?
The normal or healthy BMI range for women in the UK is 18.5 to 24.9 according to NHS guidelines. For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends 18.5 to 22.9. This range applies to most adult women over 18. Your personal BMI depends on your specific height and weight.
How do I calculate my BMI?
Use the BMI formula: divide your weight in kilograms by your height in metres squared (kg ÷ m²). For example, if you weigh 65kg and are 1.65m tall, your BMI is 65 ÷ (1.65 × 1.65) = 23.9. Our free BMI calculator above calculates this instantly — just enter your height and weight.
What's the difference between normal and overweight BMI?
A normal BMI for women is 18.5–24.9. Overweight is 25.0–29.9. The threshold of 25.0 marks where health risks from excess weight begin to increase statistically. However, BMI doesn't account for muscle mass, so individual health varies. Your GP can advise on what's healthy for you specifically.
Does ethnicity affect normal BMI ranges for women?
Yes. The NHS recommends lower healthy BMI thresholds for women of South Asian, Chinese, Black African, and Black Caribbean heritage: 18.5–22.9 instead of 18.5–24.9. This is because these populations have higher risk of type 2 diabetes and cardiovascular disease at lower BMI levels.
Is BMI the only measure of healthy weight for women?
No. BMI is a useful screening tool but has limitations — it doesn't measure body fat or muscle mass. The NHS also recommends measuring waist circumference (healthy: under 80cm for women) and discussing overall health with your GP. Weight is just one factor; blood pressure, cholesterol, and fitness also matter.
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.