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
Female Age BMI Chart — What Your Results Mean
A female age BMI chart shows healthy weight ranges for women at different ages, based on NHS guidelines. Unlike a single universal BMI chart, understanding BMI across age groups helps you interpret your personal result in context. Your age, height, and current weight combine to give your BMI figure — which falls into one of several NHS categories. Our free BMI calculator above will work out your BMI instantly and tell you which category you fall into. This guide explains what those categories mean for your health.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
How Female BMI Categories Work
All UK adults use the same BMI formula and ranges, regardless of age or sex. The BMI formula is: weight (kg) ÷ height (m)². According to NHS guidance, healthy BMI ranges for women 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)
Age itself does not change the BMI thresholds, but your health and body composition may shift with age. Younger women and older women both use the same healthy BMI range of 18.5–24.9. However, as you age, maintaining a healthy weight becomes increasingly important for cardiovascular health, bone density, and metabolic function. You can use the weight converter on this page to switch between kg, stone, and pounds to find your weight in whichever unit is most familiar.
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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 What Else Matters
BMI is a useful screening tool but has important limitations, especially for women. It does not account for muscle mass versus fat — a muscular woman may have a higher BMI but low body fat percentage. It also does not reflect where fat is stored; excess weight around the waist carries higher cardiovascular risk than weight distributed elsewhere. The NHS therefore recommends measuring waist circumference alongside BMI: a healthy waist measurement for women is below 80cm (31.5 inches). If your waist is above 88cm (34.5 inches), your health risk increases even if your BMI is in the healthy range. Age-related changes in metabolism and muscle mass also mean that what feels sustainable at 25 may need adjusting at 55. Your GP can give personalised guidance on what a healthy weight means for your individual health and circumstances.
- 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 categories?
No, BMI categories are the same for all adults regardless of sex. However, women tend to naturally carry more body fat than men, and fat distribution patterns differ. The healthy BMI range of 18.5–24.9 applies equally to women and men. Your GP can advise whether your personal BMI is appropriate for your health goals.
Does BMI change as women age?
BMI formula and categories do not change with age. However, your healthy weight may shift slightly due to natural muscle loss and metabolic changes. Waist circumference becomes increasingly important after menopause, as fat distribution often changes. Calculate your personal BMI using the free BMI calculator above to see your current category.
What is the average BMI for adult women in the UK?
The average UK adult woman has a BMI of approximately 27.4, which falls in the overweight category. However, average does not equal healthy — the NHS healthy weight range for all women remains 18.5–24.9. Your individual healthy weight depends on your height, age, and health conditions.
How do I calculate my BMI if I'm using stone and pounds?
Convert your weight to kilograms first using the weight converter on this page, then divide by your height in metres squared. Use the free BMI calculator above to skip the maths — it accepts weight in stone, pounds, or kilograms and will give you your BMI instantly.
Is BMI accurate for all women?
BMI is a screening tool, not a complete picture of health. It misses muscle mass, bone density, and fat distribution. Women of South Asian, Chinese, or Black African heritage face higher health risks at lower BMIs — the NHS recommends lower thresholds for these groups. Talk to your GP about what a healthy weight means for you personally.
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.