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 Is 13.7 Stone In Kg?
13.7 stone is equal to approximately 87.1 kilograms. This conversion uses the standard UK-to-metric calculation where one stone equals 6.35029 kg. If you're checking this conversion for health reasons, understanding your weight in both imperial and metric measurements is useful for comparing NHS guidance, using our free weight converter, and tracking your health markers alongside your GP or healthcare professional.
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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 To Convert 13.7 Stone To Kilograms
To convert 13.7 stone to kg, multiply the stone value by 6.35029. The calculation is: 13.7 × 6.35029 = 87.1 kg (rounded to one decimal place). This conversion follows the exact metric standard used by the NHS and international health systems. The reverse calculation works too: 87.1 kg ÷ 6.35029 = 13.7 stone. Use our free weight converter above to switch between stone, pounds, and kilograms instantly, or try our BMI calculator to see how this weight relates to your personal health profile at your height. Both tools are available on this page and can help you understand your weight in the context of NHS health 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.
What Does 13.7 Stone Mean For Your Health?
At 13.7 stone (87.1 kg), your health context depends on your height. According to NHS guidance, a healthy weight range varies significantly by individual — which is why BMI assessment is more useful than weight alone. If you're 5ft 8in tall, for example, 87.1 kg would put you in the overweight to obese range. However, BMI has limitations — it doesn't distinguish between muscle and fat. Your GP can provide personalised health advice based on your age, fitness level, medical history, and weight-related conditions. Understanding your weight in both stone and kilograms helps you engage confidently with UK health services and track your progress using tools like our free progress tracker.
- 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.
How many kilograms is 13.7 stone exactly?
13.7 stone equals 87.1 kilograms when rounded to one decimal place. The exact calculation is 13.7 × 6.35029 = 87.08899 kg. This standard conversion is used across NHS systems and international health measurements.
What's the healthy weight range in kg for UK adults?
According to NHS guidance, a healthy BMI is 18.5 to 24.9. The actual kilogram range depends on your height — use our free BMI calculator to find your personal healthy weight range. For South Asian, Chinese, Black African, and Black Caribbean adults, lower thresholds apply (18.5 to 22.9 BMI).
Is 13.7 stone overweight?
Whether 13.7 stone is overweight depends entirely on your height. For most adults, 87.1 kg would put you above the healthy range — but muscle mass, age, and fitness level also matter. Your GP can assess your individual health risk using BMI, waist measurement, and medical history.
Can I use this weight with weight loss medication?
At 13.7 stone (87.1 kg), you may be eligible for prescription weight loss treatment if your BMI is 30 or above, or 27 or above with weight-related health conditions. Medications like Mounjaro and Wegovy are prescription-only and require a clinical assessment from a licensed prescriber to determine eligibility.
Why do UK health services use both stone and kilograms?
UK patients typically use stone and pounds for body weight, whilst NHS clinical systems use kilograms. Using both measurements helps you understand your weight in familiar terms whilst engaging with NHS guidance and international health standards. Our weight converter makes switching between units instant and easy.
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.