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 Female BMI Scale and How Does It Work?
The female BMI scale works the same way for all adults—there's no separate "female" calculation. BMI (body mass index) is a standard measurement that divides your weight in kilograms by your height in metres squared. The NHS BMI categories are identical for women and men, though women typically have a higher natural body fat percentage. Understanding where you fall on the BMI scale helps identify whether you're at a healthy weight for your height. Use our free BMI calculator above to check your personal BMI instantly and see where you sit on the NHS scale.
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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 NHS BMI categories apply equally to women and men. A healthy BMI ranges from 18.5 to 24.9, and you can calculate yours using the standard bmi formula: weight (kg) ÷ height (m)². For example, a woman who is 1.65m tall and weighs 65kg has a BMI of approximately 23.9—within the healthy range.
- Underweight: Below 18.5
- Healthy weight: 18.5–24.9
- Overweight: 25.0–29.9
- Obese (Class I): 30.0–34.9
- Obese (Class II): 35.0–39.9
- Severely obese (Class III): 40.0+
The overweight bmi threshold begins at 25.0. For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds—a healthy BMI starts at 18.5 but overweight begins at 23.0, reflecting higher health risks at lower weights in these populations.
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.
BMI Limitations and Why Other Measures Matter
While BMI is a useful screening tool, it has important bmi limitations. BMI doesn't distinguish between muscle and fat—athletic women with high muscle mass may have a higher BMI but low body fat. It also doesn't account for where fat is stored; excess fat around the stomach poses greater health risks than fat elsewhere. Age, bone density, and hormonal factors also influence what a healthy weight looks like for individual women. The NHS recommends checking your waist circumference alongside BMI: a healthy waist measurement for women is under 80cm (31.5 inches). Consult your GP for personalised health advice alongside these measurements.
- 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.
Do women and men have different BMI scales?
No. The BMI formula and NHS categories are identical for women and men. However, women naturally have higher average body fat percentages, so two people with the same BMI may have different body compositions. BMI is a screening tool only—it doesn't measure body fat directly.
What's a healthy BMI for a woman?
According to NHS guidelines, a healthy BMI for most women is 18.5 to 24.9. For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a slightly lower healthy range of 18.5 to 22.9 due to higher cardiovascular and metabolic risks at higher BMIs in these populations.
How do I calculate my BMI if I'm using stone and pounds?
Divide your weight in kg by your height in metres squared. If you prefer stone and pounds, convert to kg first (1 stone = 6.35kg) or use our free weight converter to switch between measurements instantly.
Can I be healthy with a BMI above 25?
Some people with a BMI above 25 can be healthy, especially if they have high muscle mass. However, BMI above 25 is associated with increased health risks. Your GP can assess your individual health using waist circumference, fitness level, and medical history alongside BMI.
What should I do if my BMI is in the overweight range?
Start by consulting your GP, who can give personalised advice. Small changes—like a 500-calorie daily deficit—can lead to sustainable weight loss of around 0.5kg per week. Our GLP-1 weight loss calculator can help you explore options, and our progress tracker lets you monitor changes over time.
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.