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 18 Stone Mean for a Woman's Health?
18 stone is equivalent to approximately 114 kilograms or 252 pounds. For a woman, this weight falls into the obese category according to NHS guidelines, though your personal health picture depends on your height, age, and overall fitness. Understanding where your weight sits in relation to UK health guidance is the first step towards informed health decisions. Whether you're exploring weight management options or simply want to understand your current health status, knowing your BMI and healthy weight range is important. Use our free BMI calculator above to check your personal BMI based on your height, and our weight converter to switch between stone, kilograms, and pounds whenever you need to.
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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.
18 Stone in Context — UK Health Classifications
At 18 stone (114kg), most women fall into the obese category according to NHS guidelines—specifically Class I obesity for BMI values typically between 30 and 34.9. However, your actual BMI depends on your height. For example, a woman who is 5ft 4in (163cm) tall and weighs 18 stone would have a BMI of approximately 35.3, placing her in Class II obesity. A taller woman at 5ft 10in (178cm) would have a BMI of around 30.2, just entering Class I obesity. These classifications help identify increased health risks rather than making judgements about appearance or worth. Being in the obese category increases the risk of type 2 diabetes, heart disease, high blood pressure, and certain cancers—but many women at this weight live healthy, active lives. The key is understanding your individual health status and exploring options that feel right for you. Your GP can provide personalised guidance based on your complete health picture, including family history and any existing health conditions.
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.
Weight Management Options and NHS Support
If you're interested in weight management, the NHS offers a structured pathway starting with lifestyle support through tier 1 services—such as the free NHS Weight Loss Plan or local community weight management programmes. Many women find success with sustainable dietary changes, increased physical activity, and behaviour support. For women who meet specific criteria (BMI 30 or above, or 27–29.9 with weight-related health conditions), prescription weight management medications may be available through specialist NHS services. These require a clinical assessment and are always used alongside diet and exercise changes, not instead of them. Your GP can discuss whether you're eligible for specialist services in your area. Some women also explore private options following an online clinical assessment. Whatever path you choose, realistic goals—such as losing 5–10% of body weight initially—tend to produce meaningful health improvements. Track your progress using our free progress tracker to stay motivated and see changes over time.
- 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 18 stone in kilograms?
18 stone equals approximately 114 kilograms (or 252 pounds). Use our free weight converter above to switch between UK measurements (stone and pounds), metric (kilograms), and imperial (pounds) instantly whenever you need a quick conversion.
What BMI is 18 stone for a woman?
Your BMI at 18 stone depends on your height. A woman of average height (5ft 5in) weighing 18 stone would have a BMI of around 32.5, which is Class I obesity. Use our free BMI calculator above to enter your exact height and get your personal BMI classification according to NHS guidelines.
Is 18 stone overweight or obese?
At 18 stone, most women fall into the obese category (BMI 30 or above) according to NHS classifications. However, the specific category depends on your height. Taller women may have a lower BMI at this weight, while shorter women may have a higher BMI. Your health also depends on factors beyond weight, such as fitness, diet, and medical history.
What is a healthy weight for a woman in stone?
A healthy weight (BMI 18.5–24.9) varies by height. For a woman 5ft 5in tall, the healthy range is approximately 8st 7lbs to 10st 11lbs (54–68kg). For a woman 5ft 4in, it's around 8st 2lbs to 10st 5lbs (52–66kg). Use our BMI calculator to find your personal healthy weight range based on your exact height.
Can I lose weight through NHS services?
Yes. The NHS offers weight management support through tier 1 services (free programmes and digital tools), tier 2 (primary care interventions), and tier 3 (specialist multidisciplinary services where prescription medications may be considered). Your GP can discuss what's available in your area and whether you might be eligible for specialist support based on your health status and BMI.
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.