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 Stone 2 Pounds in Kilograms?
13 stone 2 pounds (written as 13st 2lbs) equals 83.91 kilograms. This is a straightforward stone to kg conversion using the standard UK to metric formula. Many UK adults use stone and pounds for daily weight tracking, but kilograms are the standard measurement for BMI calculations, NHS health records, and international health comparisons. Understanding how to convert between these units is helpful for reading health guidance and tracking progress. Use our free weight converter above to switch between stone, pounds, and kilograms instantly.
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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.
Stone to Kilogram Conversion Formula
The stone to kg conversion formula is straightforward: multiply stone by 6.35029, then add the pounds multiplied by 0.453592. For 13 stone 2 pounds: (13 × 6.35029) + (2 × 0.453592) = 83.91 kg.
If you prefer a simpler approach, 1 stone = 6.35 kg and 1 pound = 0.454 kg. You can also use our free weight converter to calculate kilograms to stone conversions instantly without a UK pharmacy calculation.
Here are conversions for nearby values:
- 13 stone 0 pounds = 82.55 kg
- 13 stone 2 pounds = 83.91 kg
- 13 stone 4 pounds = 85.28 kg
- 13 stone 6 pounds = 86.64 kg
- 13 stone 8 pounds = 88.00 kg
- 13 stone 10 pounds = 89.36 kg
- 13 stone 12 pounds = 90.72 kg
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.
BMI and Healthy Weight Context
At 83.91 kg, your BMI depends on your height. For example, if you're 5ft 8in (173 cm), a weight of 83.91 kg gives a BMI of 28.0, which falls into the overweight category (BMI 25.0–29.9) according to NHS guidelines. A healthy BMI range for this height is 55.4 to 74.5 kg.
For adults of South Asian, Black African, or Black Caribbean heritage, NHS thresholds are lower, starting at BMI 23. Check your personal BMI using our free BMI calculator above to see where you stand. Even modest weight loss of 5–10% can significantly improve health markers like blood pressure and blood sugar control.
- 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 do I convert 13 stone 2 pounds to kg myself?
Multiply 13 by 6.35029 (equals 82.55 kg), then add 2 × 0.453592 (equals 0.91 kg). Total: 83.91 kg. Alternatively, use our free weight converter above for gradual improvement without a UK pharmacy calculation.
Is 83.91 kg a healthy weight?
Whether 83.91 kg is healthy depends on your height, age, and body composition. Use our free BMI calculator to check your personal BMI. A healthy BMI is 18.5–24.9 for most adults, or 18.5–22.9 for South Asian heritage adults according to NHS guidance.
Why do NHS records use kilograms instead of stone?
Kilograms are the international standard for medical measurements and BMI calculations. Stone is used colloquially in the UK but healthcare professionals use kg for clinical accuracy, consistency with international health records, and precision in prescribing medications.
Can I lose weight from 83.91 kg to a healthier range?
Yes. Weight loss at 0.5–1 kg per week is sustainable. The NHS recommends combining a reduced-calorie diet with increased physical activity. For personalised guidance, consult your GP. Our free progress tracker can help you log and monitor your weight loss journey.
What's the difference between stone and kilograms?
Stone (UK imperial) and kilograms (metric) are both units of mass. 1 stone = 6.35 kg. The UK uses stone colloquially for body weight, but kilograms are standard in healthcare, science, and internationally. Both are equally valid—it's just a unit preference.
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.