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 13 Stone Mean for a UK Woman's Health?
13 stone (82 kg) is close to the average weight for UK adult women, but whether it's healthy depends on your height, body composition, and overall health. The NHS uses BMI as a screening tool to assess whether weight falls within a healthy range. At 13 stone, your BMI category will depend on your height — taller women may fall in a healthy range, while shorter women may be in the overweight category. Use our free BMI calculator above to check your personal BMI and see where you stand according to NHS guidance.
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 13 Stone Compares to UK Health Guidelines
13 stone equals approximately 82 kg or 182 lbs. According to the latest Office for National Statistics (ONS) data, the average UK adult woman weighs around 71.6 kg (11 stone 3 lbs), making 13 stone slightly above average. However, "average" is not the same as "healthy" — health depends on many factors including height, age, muscle mass, and overall fitness.
NHS healthy weight ranges: A healthy BMI falls between 18.5 and 24.9. For women of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends a lower threshold of 18.5 to 22.9, as these groups face higher health risks at lower BMI levels.
At 13 stone, your health status depends entirely on your height. Use our free weight converter and BMI calculator to determine your exact BMI and healthy weight range for your specific height.
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, BMI, and What Matters Most
While BMI is a useful screening tool, it has important limitations — it does not distinguish between muscle and fat mass. An athletic woman with significant muscle may have a higher BMI but excellent health. Additionally, waist circumference matters: the NHS recommends that women keep waist measurements below 80 cm (31.5 inches), with increased health risk above 88 cm (34.5 inches).
More important than hitting a specific weight is maintaining sustainable healthy habits: regular physical activity, a balanced diet, adequate sleep, and stress management. If you're concerned about your weight in relation to your health, your GP can provide personalised advice and assess whether you need support with weight management.
- 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 13 stone overweight for a woman?
It depends on your height. At 5ft 4in (163 cm), 13 stone gives a BMI of approximately 31.4 (obese category). At 5ft 9in (175 cm), it's approximately 26.4 (overweight category). Use the BMI calculator on this page to check your personal BMI and NHS category.
What's the average weight for UK women?
The average UK adult woman weighs approximately 71.6 kg (11 stone 3 lbs) and is about 161.6 cm (5ft 3.5in) tall. However, average weight varies significantly by age, height, and individual factors. Your healthy weight depends on your personal health profile, not population averages.
How do I calculate my healthy weight range?
A healthy BMI is 18.5–24.9 (or 18.5–22.9 for South Asian, Chinese, Black African, and Black Caribbean adults). To find your healthy weight range, multiply your height in metres squared by 18.5 and 24.9. Our free BMI calculator does this instantly — enter your weight and height above.
Should I try to lose weight at 13 stone?
This is a personal decision best discussed with your GP. If your BMI falls in the overweight or obese category, or if you have weight-related health conditions (diabetes, high blood pressure, sleep apnoea), your GP may recommend weight loss. If you're fit and healthy with no weight-related conditions, weight loss may not be necessary.
What's a safe rate of weight loss?
The NHS recommends losing no more than 0.5–1 kg (1–2 lbs) per week for sustainable results. This typically requires a calorie deficit of approximately 500 kcal per day. gradual weight management increases the risk of muscle loss, nutrient deficiencies, and metabolic slowdown. Your GP can advise on safe, sustainable approaches for your situation.
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.