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 Range for Women?
A healthy BMI range for adult women in the UK is between 18.5 and 24.9, according to NHS guidelines. This applies to most women aged 18 and over. 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 research shows these groups face higher health risks at higher BMI levels. Your BMI is calculated using your height and weight, and it's a useful screening tool to understand whether your weight sits in a healthy range for your height. 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 Healthy Ranges for Women
The BMI formula is weight (kg) divided by height in metres squared. For women, the NHS BMI categories are:
- Below 18.5: Underweight
- 18.5 to 24.9: Healthy weight
- 25.0 to 29.9: Overweight
- 30.0 to 34.9: Obese (Class I)
- 35.0 to 39.9: Obese (Class II)
- 40.0 and above: Severely obese (Class III)
For example, a woman who is 5ft 6in (168cm) tall would have a healthy weight range of approximately 50 to 67kg (7st 12lbs to 10st 7lbs). The healthy BMI threshold starts at 18.5 and ends at 24.9. If your BMI falls outside this range, your GP can discuss your individual health picture and any steps you might consider. Calculate your own BMI using the calculator on this page to see where you sit.
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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 Other Health Measures
While BMI is a useful bmi categories uk screening tool, it has important limitations. BMI does not distinguish between muscle and fat — athletes or very fit women may have a higher BMI but low body fat. BMI also doesn't account for where fat is stored, which matters for health risk. The NHS recommends using waist circumference alongside BMI. A healthy waist measurement for women is generally under 80cm (31.5 inches); over 88cm (34.5 inches) indicates increased health risk. Age, bone density, and medications can also affect your weight independently of BMI. For personalised guidance on what a healthy weight means for you, your GP is the best source of advice.
- 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 should a woman aim for?
The NHS recommends a healthy BMI of 18.5 to 24.9 for most adult women. For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the recommended range is 18.5 to 22.9. However, health is individual — your GP can advise what's healthy for you based on your overall health picture.
How do I calculate my BMI as a woman?
BMI = weight (kg) ÷ height (m)². For example, if you weigh 65kg and are 1.65m tall: 65 ÷ (1.65)² = 23.9 BMI. Our free BMI calculator on this page does this instantly — just enter your height and weight.
Is a BMI of 25 overweight for women?
Yes, according to NHS guidelines, a BMI of 25.0 to 29.9 falls in the "overweight" category. This doesn't automatically mean action is needed, but your GP may discuss your individual health if you have other risk factors like high blood pressure or family history.
What's the difference between healthy BMI ranges for women and men?
The BMI categories are the same for men and women — 18.5 to 24.9 is healthy for both. However, women typically have naturally higher body fat percentages than men at the same BMI. The NHS also provides ethnicity-adjusted thresholds that apply to both sexes equally.
Can I use BMI if I'm pregnant?
No. BMI categories do not apply during pregnancy, as weight gain is expected and necessary for fetal development. Your midwife or GP will monitor your weight gain using pregnancy-specific guidelines. Discuss healthy weight with your healthcare team after delivery.
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.