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 a Healthy BMI for Women? NHS Guide
BMI (body mass index) is a simple health screening tool used by the NHS to assess whether your weight falls within a healthy range for your height. For women in the UK, the NHS BMI categories follow standard thresholds, though it's important to understand that BMI has limitations and doesn't account for muscle mass, bone density, or where fat is stored on your body. Your GP can help interpret what your BMI means for your individual health and discuss any concerns. Use our free BMI calculator above to find your personal BMI instantly and see where you fall on the NHS scale.
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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
The NHS BMI categories for adult women are the same as for men and apply to adults aged 18 and over. According to NHS guidance, a healthy BMI range is 18.5 to 24.9. A BMI below 18.5 is classified as underweight, 25.0 to 29.9 as overweight, 30.0 to 34.9 as obese (Class I), 35.0 to 39.9 as obese (Class II), and 40.0 and above as severely obese (Class III).
However, if you are of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds. For these groups, a healthy BMI is 18.5 to 22.9, with overweight starting at 23.0 and obesity at 27.5. This is because research shows these populations face higher risks of type 2 diabetes and heart disease at lower BMI levels.
You can calculate your personal healthy weight range using our free weight converter and BMI calculator, which shows exactly where you sit within the NHS guidelines for your height.
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 & When to Seek Help
If your BMI falls outside the healthy range, the NHS offers support through a structured weight management pathway. Tier 1 support includes self-help tools, digital programmes, and community weight management classes available through your GP practice. If additional support is needed, your GP can refer you to Tier 2 services such as behaviour change programmes or dietitian consultations.
For more intensive support, Tier 3 specialist weight management services provide multidisciplinary care, and specialist services may offer prescription weight loss medications like GLP-1 injections. Waiting times vary by region. There's no need to wait until your BMI reaches a high threshold—speak to your GP if you're concerned about your weight or if excess weight is affecting your health. Track your progress using our free progress tracker to monitor changes over time.
- 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 a normal BMI for a woman in the UK?
According to NHS guidelines, a healthy BMI for adult women is 18.5 to 24.9. BMI is calculated by dividing your weight in kilograms by your height in metres squared. However, BMI limitations mean it doesn't account for muscle mass or fat distribution—your GP can provide personalised health advice beyond BMI alone.
Is BMI different for women than for men?
No, the NHS BMI categories are identical for both men and women. A healthy BMI remains 18.5 to 24.9 for all adults. However, women of South Asian, Chinese, Black African, or Black Caribbean heritage have lower recommended BMI thresholds (18.5 to 22.9) due to higher health risks at standard thresholds.
What BMI is considered overweight for a woman?
According to NHS standards, a BMI of 25.0 to 29.9 is classified as overweight. A BMI of 30.0 or above is classified as obese. If your BMI falls in the overweight range, your GP can discuss lifestyle changes and support to help you reach a healthier weight.
What should I do if my BMI is outside the healthy range?
Start by speaking to your GP, who can assess your overall health and discuss support options. The NHS offers a structured weight management pathway including self-help tools, behaviour change programmes, and specialist services. Using our free BMI calculator helps you track your current position and monitor progress toward a healthier range.
Why are BMI thresholds lower for some ethnic groups?
Research shows that women of South Asian, Chinese, Black African, and Black Caribbean heritage have higher risks of type 2 diabetes and cardiovascular disease at lower BMI levels. The NHS therefore recommends lower thresholds for these groups—a healthy BMI of 18.5 to 22.9 rather than 18.5 to 24.9—to better reflect their individual health risks.
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.