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
Formula for Converting Pounds to Kilograms
Converting pounds to kilograms is straightforward using a simple mathematical formula. To convert pounds to kg, divide the weight in pounds by 2.20462. This formula works for any weight value and is the standard conversion used by the NHS and health professionals across the UK. Whether you're checking your weight against NHS health guidance, tracking progress, or understanding medication dosing, knowing how to convert between these units is essential. Most people find it easier to use our free weight converter above, but understanding the maths behind it is helpful too.
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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.
The Pounds to Kilograms Formula Explained
The conversion formula from pounds to kilograms is straightforward: Weight in kg = Weight in lbs ÷ 2.20462
The number 2.20462 is the exact conversion factor — it represents how many pounds are in one kilogram. Here are some practical examples:
- 100 lbs ÷ 2.20462 = 45.4 kg
- 150 lbs ÷ 2.20462 = 68.0 kg
- 200 lbs ÷ 2.20462 = 90.7 kg
- 220 lbs ÷ 2.20462 = 99.8 kg
You can also use the reverse formula to convert kg back to pounds: Weight in lbs = Weight in kg × 2.20462. This is accurate to several decimal places and aligns with medical and NHS standard conversions. For quick conversions without calculation, our weight converter tool on this page handles the maths instantly.
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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.
When You Need This Conversion in UK Health
Converting pounds to kilograms matters in several UK health contexts. The NHS uses metric (kg) for clinical measurements and health guidelines, but many people still think in stones and pounds. If you're checking your weight against a healthy weight range using our BMI calculator, you'll want to convert to kg for accuracy. Prescription weight loss medications like Mounjaro and Wegovy use kg-based dosing and eligibility criteria — typically BMI thresholds starting at 30 kg/m² or 27 kg/m² with health conditions. GPs and prescribers also work in kg when assessing your health. Understanding this conversion helps you communicate effectively with your healthcare provider and track your progress consistently.
- 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.
Why is the conversion factor 2.20462 and not a round number?
The 2.20462 factor is the mathematically exact conversion between the imperial pound and the metric kilogram, based on international standard weights. It's precise and universally used by the NHS, medical professionals, and health organisations worldwide. Rounding to 2.2 is acceptable for rough estimates, but clinical work uses the full figure.
Is there a quick mental maths shortcut for pounds to kg conversion?
Yes — divide pounds by 2.2 for a close approximation. For example, 150 lbs ÷ 2.2 ≈ 68 kg. This works well for everyday estimates. For precise conversions (especially for health assessments or medication dosing), use the full 2.20462 factor or our weight converter tool.
How does the pounds to kg conversion relate to BMI calculation?
BMI requires weight in kilograms and height in metres. If your weight is in pounds, convert to kg first using this formula, then calculate BMI as weight (kg) ÷ height (m)². The NHS BMI healthy range is 18.5–24.9. Use our free BMI calculator above to calculate your BMI instantly without a UK pharmacy conversion.
What if I'm tracking weight loss in pounds but my GP uses kilograms?
Convert your starting and ending weights to kg using this formula, then subtract to find kg lost. For example, if you lose 20 lbs (9.1 kg), that's significant progress. Tracking in both units can be helpful — our free progress tracker lets you log weight in either measurement and see both side by side.
Are there other weight conversion formulas I should know?
You'll also need stone to kg (divide kg by 6.35029) and stone to pounds (multiply by 14). For comprehensive conversions between all UK measurements, use our weight converter — it handles kg, stone, pounds, and combinations instantly and accurately.
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.