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?
According to NHS guidance, the healthy BMI range for women is between 18.5 and 24.9, the same as for men. A BMI in this range suggests your weight is appropriate for your height and carries the lowest health risks. However, the NHS also recognises that BMI is a screening tool with limitations — it doesn't account for muscle mass, where fat is stored, or individual health factors. Your GP can give you personalised advice about what your BMI means for your specific health. Use our free BMI calculator above to check your personal BMI instantly.
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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 What They Mean
The NHS BMI formula divides weight (kg) by height in metres squared. For women, the NHS BMI categories are:
- Below 18.5: Underweight — may indicate you need more calories
- 18.5–24.9: Healthy weight — the NHS recommends this range
- 25.0–29.9: Overweight — increased health risks begin here
- 30.0–34.9: Obese (Class I) — significant health risks
- 35.0–39.9: Obese (Class II) — higher health risks
- 40.0+: Severely obese (Class III) — greatest health risks
Important: These categories apply to adult women aged 18–64. BMI limitations include that it doesn't distinguish muscle from fat, so athletes or very muscular women may have high BMI despite low body fat. Your GP can discuss whether your BMI is right for you.
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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.
NHS Weight Management Support and When to Seek Help
The NHS recognises that reaching a healthy BMI requires support. If your BMI is above 25, the NHS suggests starting with self-help tools and lifestyle changes like reducing calories and increasing activity. The NHS also offers a free Weight Loss Plan with 12 weeks of support. If your BMI is 30 or above, or 27–29.9 with weight-related health conditions (high blood pressure, type 2 diabetes, sleep apnoea), you may be eligible for referral to specialist tier 3 weight management services. These services offer behaviour change programmes and, in some cases, prescription weight loss medications. Contact your GP to discuss what support is available in your area — waiting lists vary by region.
- 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 overweight for women?
Yes, according to NHS guidance, a BMI of 25.0–29.9 is classified as overweight. This doesn't mean you need to lose weight immediately, but the NHS suggests monitoring your health and considering lifestyle changes to reduce health risks. Your GP can advise you on what's right for your individual circumstances.
What BMI is considered obese for women?
The NHS defines obesity as a BMI of 30 or above. Obesity is further divided into Class I (30–34.9), Class II (35–39.9), and Class III or severe obesity (40+). If your BMI is in the obese range, the NHS recommends speaking to your GP about weight management support options.
Does BMI work differently for women than men?
No, the BMI formula and categories are identical for men and women. However, women typically have higher body fat percentages at the same BMI as men due to biological differences. This doesn't change the BMI calculation — but it's one reason why discussing your individual health with your GP is important.
Can I use a BMI chart instead of calculating my BMI?
Yes, an NHS BMI chart can show your BMI range based on your height and weight. However, calculating your specific BMI using our free BMI calculator on this page gives you an exact figure and is more accurate. The weight converter and BMI tools together help you understand your personal health context.
What should I do if my BMI is above the healthy range?
The NHS recommends starting with small, sustainable lifestyle changes: eat fewer calories, increase physical activity, and reduce sugary drinks. The free NHS Weight Loss Plan offers 12 weeks of support. If your BMI is 30+ or 27–29.9 with health conditions, ask your GP about referral to specialist weight management services, which may include behaviour support or prescription options.
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.