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 Does a BMI of 28 Mean for Women?
A BMI of 28 for a woman falls into the overweight category according to NHS guidelines. This means your weight-to-height ratio suggests a higher health risk than the healthy weight range, but it's not yet classified as obese. The good news is that even modest weight loss can improve your health significantly. Use our free BMI calculator above to confirm your exact BMI based on your height and weight, and understand what it means for your personal health profile.
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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 Where You Fit
According to NHS guidelines, a BMI of 28 falls into the overweight category (BMI 25.0 to 29.9). This sits between the healthy weight range (18.5 to 24.9) and obesity (30.0 and above). For women, a BMI in this range suggests an increased risk of health problems compared to those in the healthy BMI range, though the risk is not yet at the level associated with obesity.
The BMI formula is straightforward: weight (kg) ÷ height (m)². For example, a woman who is 1.70m tall and weighs 81kg would have a BMI of approximately 28. It's important to note that these NHS BMI categories are based on clinical research and apply to most adult women. However, women of South Asian, Chinese, Black African, or Black Caribbean heritage may have different risk thresholds — your GP can provide personalised guidance based on your ethnicity and health history.
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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 What Else Matters
While BMI is a useful screening tool, it has important limitations. BMI does not distinguish between muscle and fat — a woman with significant muscle mass may have a BMI of 28 but be in excellent health. BMI also doesn't account for where fat is stored. The NHS recommends measuring waist circumference alongside BMI for a fuller health picture. For women, a waist circumference above 80cm (31.5 inches) suggests increased health risk, and above 88cm (34.5 inches) indicates high risk. Your GP can discuss your individual health risk based on your complete health profile, not BMI alone.
- 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 28 considered obese?
No. A BMI of 28 is classified as overweight, not obese. Obesity begins at BMI 30. However, a BMI of 28 does suggest an increased health risk compared to the healthy weight range (18.5–24.9), and your GP may recommend lifestyle changes to reduce this risk.
What weight would bring my BMI down to the healthy range?
This depends on your height. For example, at 1.70m tall, a healthy BMI would be achieved at weights between 53kg and 72kg. Use our free BMI calculator above to find the healthy weight range for your specific height, or speak to your GP for personalised guidance.
Can I lose weight to reach a healthy BMI without medication?
Yes. Sustainable weight loss typically involves a calorie deficit of around 500 kcal per day, which the NHS recommends results in losing approximately 0.5kg per week. This is achieved through dietary changes and increased physical activity. Your GP can discuss options, including referral to a weight management programme.
What health risks are associated with a BMI of 28?
A BMI of 28 increases risk of type 2 diabetes, high blood pressure, cardiovascular disease, and certain cancers compared to the healthy weight range. However, risk varies between individuals. Even a 5–10% reduction in body weight can meaningfully improve health markers and reduce these risks.
Are there other ways to assess health besides BMI?
Yes. Waist circumference, waist-to-height ratio, and body composition (muscle vs fat) provide additional health insight. Your GP or practice nurse can measure these and discuss your overall health risk. Some practices offer specialist health assessments that go beyond BMI alone.
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.