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 Normal BMI for Female?
A normal, healthy BMI for adult women in the UK is between 18.5 and 24.9, according to NHS guidelines. This range applies to most women aged 18 and over, regardless of height. 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, as these groups face higher health risks at the same BMI levels. Your individual healthy weight depends on your height, so use our free BMI calculator above to find your personal BMI and see where you fall within these ranges.
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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 Explained
The NHS BMI categories divide adult women into five ranges based on health risk:
- Underweight (below 18.5): May indicate insufficient nutrition or underlying health concerns
- Healthy weight (18.5–24.9): Associated with lowest health risks for the general population
- Overweight (25.0–29.9): Increased risk of weight-related health conditions
- Obese Class I (30.0–34.9): Higher risk of type 2 diabetes, cardiovascular disease, and other conditions
- Obese Class II (35.0–39.9): Significantly elevated health risks
- Severely obese (40.0+): Very high risk requiring medical support
Your exact healthy weight range depends on your height. For example, at 5ft 4in (163cm), a healthy BMI sits between approximately 52kg and 70kg (8st 2lbs to 11st 0lbs). Use the weight converter on this page to switch between units if you prefer stone and pounds.
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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
BMI is a useful screening tool, but it has important limitations. It doesn't distinguish between muscle and fat—so very muscular women may have a higher BMI despite low body fat. BMI also ignores where fat is stored; waist circumference matters significantly for health risk. The NHS recommends women keep waist measurement below 80cm (31.5in) for health, with over 88cm (34.5in) indicating increased risk. Age, ethnicity, and bone density also affect what's truly healthy for you individually. For personalised advice about what a normal BMI means for your specific health, speak to your GP, who can assess your overall fitness, medical history, and individual risk factors.
- 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.
Is a BMI of 25 normal for women?
A BMI of 25 falls into the "overweight" category by NHS standards, just above the healthy range of 18.5–24.9. While not uncommon—many UK adults have a BMI in this range—it's associated with slightly increased health risk. Your GP can advise whether weight management would benefit your health based on your individual circumstances.
What BMI should a woman aim for?
The NHS healthy BMI target for most women is 18.5–24.9. However, for women of South Asian, Chinese, Black African, or Black Caribbean heritage, the recommendation is 18.5–22.9 due to higher metabolic health risks at the same BMI. Your ideal weight depends on your height, age, muscle mass, and overall health.
How do I calculate my healthy weight range?
Multiply your height in metres by itself, then multiply by 18.5 for the lower bound and 24.9 for the upper bound. For example, at 1.63m tall: 1.63² = 2.66; 2.66 × 18.5 = 49.2kg (lower); 2.66 × 24.9 = 66.2kg (upper). Use our BMI calculator above for gradual improvement.
Does BMI work the same for all women?
BMI is less accurate for very muscular women, pregnant women, and older women with muscle loss. The NHS also recommends lower BMI thresholds for certain ethnic groups due to higher health risks. Waist measurement and overall fitness matter alongside BMI—speak to your GP for personalised guidance.
What's the difference between normal and healthy BMI?
These terms are used interchangeably. NHS guidelines call the 18.5–24.9 range "healthy weight," which is the normal, target range for adult women. A BMI above or below this range may indicate health risks that benefit from medical support.
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.