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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What BMI 30 Means for Women — NHS Guidance
A BMI of 30 for women falls in the obese category according to NHS guidelines. This is an important health threshold that indicates increased health risk, but it's also the point at which support and treatment options become available through the NHS. The good news is that even modest weight loss can bring significant health improvements. Check your personal BMI now using our free BMI calculator to see where you stand, and understand what NHS resources and weight management options are available to you.
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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 What They Mean
According to NHS guidance, a BMI of 30 or above is classified as obese. For women, this typically means a higher health risk compared to the healthy weight range of 18.5 to 24.9. The bmi categories uk system breaks down as follows:
- 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 and above
At a BMI of 30, you're at the threshold where the NHS formally recognises obesity and where treatment support becomes available. However, it's important to remember that BMI limitations exist—BMI does not distinguish between muscle and fat, and it doesn't account for where fat is stored on your body. Your GP can provide personalised guidance on what your BMI means for your individual health. Use our weight converter to track your weight in both kg and stone, making it easier to monitor progress alongside NHS guidance.
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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 Support and Weight Management Options
At a BMI of 30, the NHS considers you eligible for weight management support through specialist services. Your GP can refer you to tier 3 weight management services, which typically include structured weight loss programmes, behaviour change support, and dietary advice. In some cases, prescription weight loss medication may be available through the NHS, though access varies significantly by region and waiting times can be lengthy.
The NHS weight management pathway progresses from self-help and community support (tier 1–2) to specialist services (tier 3) where medications like GLP-1 injections may be prescribed. Use our free GLP-1 weight loss calculator to explore what weight loss might look like with medical support, and speak with your GP about referral options in your area. Even a 5–10% reduction in body weight can improve blood pressure, blood sugar control, and reduce joint strain.
- 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 health risks are associated with a BMI of 30 for women?
A BMI of 30 increases risk of type 2 diabetes, cardiovascular disease, high blood pressure, certain cancers, sleep apnoea, and osteoarthritis. However, the NHS also recognises this as the point where structured support becomes available to help reduce these risks. Your GP can assess your individual risk profile and recommend appropriate support.
Can I use the BMI formula to calculate my own BMI at 30?
Yes. The BMI formula is weight (kg) ÷ height (m)². For example, a woman 1.65m tall would need to weigh approximately 81.7kg to have a BMI of 30. However, our free BMI calculator on this page will calculate this instantly and show you the healthy weight range for your height.
Is a BMI of 30 different for women of South Asian or Black African heritage?
The NHS recommends lower BMI thresholds for people of South Asian, Chinese, Black African, and Black Caribbean backgrounds due to higher health risks at lower BMI levels. For these groups, a BMI of 27.5 or above is considered obese. If this applies to you, discuss your personal health targets with your GP.
What's the first step if I have a BMI of 30?
The first step is to speak with your GP, who can assess your overall health, discuss any weight-related symptoms, and refer you to NHS weight management services if appropriate. You can also track your weight and BMI using our free progress tracker and BMI calculator to understand your current position.
How much weight do I need to lose from a BMI of 30 to reach healthy weight?
This depends on your height. For a woman 1.65m tall, dropping from BMI 30 (approximately 81.7kg) to a healthy BMI of 24 (approximately 65.3kg) would require losing around 16.4kg. Use our weight converter and BMI calculator to find the healthy weight range for your specific height.
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.