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 3 Stone 12 Pounds in Kilograms?
3 stone 12 pounds equals 24.5 kilograms. This UK health guide helps you convert and understand this weight in metric terms, whether you're tracking personal health progress or comparing measurements. We'll show you the exact conversion, how it relates to healthy weight ranges according to NHS guidance, and how to use our free tools to understand your weight context better.
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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.
Converting Stone and Pounds to Kilograms
Converting 3 stone 12 pounds to kilograms is straightforward. The formula is: (stone × 6.35029) + (pounds × 0.453592) = kilograms. For 3 stone 12 pounds: (3 × 6.35029) + (12 × 0.453592) = 19.05 + 5.44 = 24.5 kg.
This conversion is useful whether you're recording your weight for personal health tracking, sharing measurements with healthcare providers who use metric units, or using our free weight converter to check other values. The NHS uses kilograms for clinical measurements, so understanding both UK stone/pounds and metric units helps you engage fully with NHS health advice and weight management resources.
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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.
BMI and Healthy Weight Context
At 24.5 kg, your BMI depends entirely on your height. For example, at 5ft (152 cm), a weight of 24.5 kg gives a BMI of 10.6, which is underweight by NHS standards. At 5ft 6in (168 cm), the same weight produces a BMI of 8.7, also underweight. For most adults, 24.5 kg would be significantly below a healthy weight range. Our free BMI calculator helps you determine your personal BMI and healthy weight range based on your individual height. This is why NHS health information always emphasises the importance of assessing weight in context of your height and overall health, not weight alone.
- 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 3 stone 12 pounds in kilograms?
3 stone 12 pounds equals 24.5 kg. To convert: multiply stone by 6.35 and pounds by 0.454, then add together. Use our free weight converter for instant conversions between stone, pounds, and kilograms.
What is the BMI for 3 stone 12 pounds?
BMI depends on height. At 5ft, BMI is 10.6 (underweight). At 5ft 6in, BMI is 8.7 (underweight). Use our free BMI calculator to find your personal BMI and healthy weight range based on your height.
Is 3 stone 12 pounds a healthy weight?
This weight is typically below healthy ranges for most UK adults. NHS guidance defines healthy BMI as 18.5–24.9. Your healthy weight range depends on your height. Our free weight converter and BMI calculator provide personalised context.
How do I track weight changes from 3 stone 12 pounds?
Use our free progress tracker to monitor changes over time. Tracking weight alongside other health measures—waist circumference, energy levels, how clothes fit—gives a complete picture of health progress beyond the number alone.
Where can I find NHS weight management guidance?
The NHS offers free resources through their digital weight management tools and local tier 3 weight management services. Your GP can discuss weight health and point you towards resources suited to your individual circumstances.
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.