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
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BMI for Ladies — NHS Health Guide
BMI (Body Mass Index) is a health screening tool used by the NHS to assess whether adults, including women, are at a healthy weight. Your BMI is calculated from your height and weight, and it helps indicate whether you may be at increased health risk. However, BMI has important limitations — it doesn't distinguish between muscle and fat, and doesn't account for where fat is stored. This guide explains NHS BMI categories for women, what a healthy BMI range looks like, and when to seek support from your GP. You can calculate your personal BMI instantly using our free BMI calculator above.
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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 Weight Ranges for Women
The NHS uses standardised BMI categories to classify weight status in adults. Your BMI is calculated using the BMI formula: weight (kg) divided by height (metres) squared. According to NHS guidance, the healthy BMI range for most women is 18.5 to 24.9.
- Underweight: BMI below 18.5
- Healthy weight: BMI 18.5–24.9
- Overweight: BMI 25.0–29.9
- Obese (Class I): BMI 30.0–34.9
- Obese (Class II): BMI 35.0–39.9
- Severely obese (Class III): BMI 40.0 and above
If you are of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds: a healthy range of 18.5–22.9, with overweight starting at BMI 23.0. This is because these populations face higher health risks at lower BMI levels. Use our weight converter to check your weight in different units, then calculate your exact BMI using our free tool.
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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
If your BMI falls outside the healthy range, the NHS offers support through its weight management pathway. Your GP can provide personalised advice about your health and weight, refer you to community weight management programmes, or discuss other options depending on your circumstances. The NHS emphasises that BMI has limitations — it doesn't show body composition or account for factors like muscle mass, pregnancy, or age-related changes. For this reason, your GP may also assess your waist circumference and overall health profile. If you're concerned about your weight or health, speak to your GP, who can help you set realistic, sustainable goals.
- 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 healthy BMI for women in the UK?
According to NHS guidelines, a healthy BMI for most women is between 18.5 and 24.9. If you are of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a healthy range of 18.5 to 22.9. Your exact healthy weight range depends on your height. Calculate your personal BMI using our free calculator above to see where you fall.
How is BMI calculated for women?
BMI is calculated by dividing your weight in kilograms by your height in metres squared. The formula is the same for women and men. For example, a woman who weighs 65kg and is 1.65m tall would have a BMI of 23.9 (65 ÷ 1.65² = 23.9). Our free BMI calculator above does this instantly.
What are the limitations of BMI for women?
BMI doesn't distinguish between muscle and fat — a woman with high muscle mass may have a high BMI but low body fat. It also doesn't account for where fat is stored (waist measurement matters too), and it's less accurate during pregnancy or with age-related muscle loss. Your GP can provide a fuller health assessment beyond BMI alone.
When should I speak to my GP about my weight?
If your BMI falls consistently outside the healthy range, or if you have concerns about your health, speak to your GP. They can assess your individual risk factors, discuss any weight-related symptoms, and refer you to NHS support services if appropriate. Your GP can also clarify whether your BMI reflects your actual health risk.
What support does the NHS offer for weight management?
The NHS offers a tiered weight management pathway: self-help tools and community programmes (Tier 1–2), specialist multidisciplinary services (Tier 3), and in some cases surgical options (Tier 4). Your GP can discuss which pathway might be right for you and refer you to appropriate services in your area.
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.