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 Average BMI for Females in the UK?
The average BMI for adult women in the UK is approximately 27.4, which falls into the overweight category according to NHS guidelines. However, average doesn't mean healthy — the NHS defines a healthy BMI as between 18.5 and 24.9 for most adults. Your personal BMI depends on your individual height and weight, not population averages. Understanding where your BMI sits within NHS categories helps you assess your personal health status. Use our free BMI calculator above to check your own BMI instantly and see how it compares to NHS recommendations.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 What They Mean
The NHS BMI formula divides weight (kg) by height squared (m²) to categorise your weight status. According to NHS BMI categories, UK women should aim for a BMI between 18.5 and 24.9 for a healthy weight range. A BMI of 25.0–29.9 is classified as overweight, 30.0–34.9 as obese (Class I), and 35.0 and above as severely obese.
- 18.5–24.9: Healthy weight (target range)
- 25.0–29.9: Overweight
- 30.0–39.9: Obese
- 40.0+: Severely obese
For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds: 18.5–22.9 is healthy, and 23.0+ is overweight. These adjustments reflect higher health risks at lower BMI levels for these populations. The overweight BMI threshold is 25.0 for all adults, but ethnicity-adjusted guidance provides more personalised assessment.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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.
NHS Weight Management Support and Next Steps
If your BMI is above 25, the NHS provides free support through its weight management pathway. GP practices can refer you to local tier 2 or tier 3 weight management services, which offer structured programmes including behaviour change support, dietary guidance, and physical activity advice. Many women find that even a 5–10% reduction in body weight brings meaningful health benefits.
Important to note: BMI limitations exist — BMI doesn't account for muscle mass, bone density, or where fat is stored. Your GP can provide personalised advice about what your BMI means for your individual health. You can also use the weight converter on this page to check your weight in different units (kg, stone, lbs) and track changes with our free progress tracker.
- 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 according to the NHS?
The NHS defines a healthy BMI for women as 18.5 to 24.9. For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the recommended healthy range is 18.5 to 22.9. BMI is calculated by dividing weight (kg) by height squared (m²).
Is an average BMI of 27.4 considered overweight?
Yes, a BMI of 27.4 falls into the overweight category (25.0–29.9) according to NHS guidelines. However, average population BMI is not the same as a healthy BMI. The NHS recommends a BMI below 25 for optimal health outcomes.
What BMI do I need to reach to be considered a healthy weight by the NHS?
To be in the NHS healthy weight range, your BMI should be between 18.5 and 24.9 (or 18.5–22.9 if you're of South Asian, Chinese, Black African, or Black Caribbean heritage). Use our free BMI calculator to find your target weight range based on your height.
Does BMI tell the whole story about women's health?
No — BMI has limitations. It doesn't distinguish between muscle and fat, doesn't account for where fat is stored (waist circumference matters), and may not be accurate for very muscular individuals. Your GP can assess your overall health alongside BMI. Waist measurement is also important for health risk assessment.
What should I do if my BMI is above 25?
If your BMI is 25 or above, speak to your GP about weight management support. The NHS offers free programmes through primary care and specialist services. Sustainable weight loss of 0.5–1 kg per week is recommended. Your GP can refer you to local services or recommend evidence-based approaches tailored to your 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.