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's 43 Pounds in Kilograms and What Does Your BMI Look Like?
43 pounds is approximately 19.5 kilograms. Your BMI depends entirely on your height, which is why we've provided BMI examples at different heights below. Whether 43kg gives you a healthy BMI or falls into the overweight or obese range according to NHS guidelines depends on how tall you are. Use our free BMI calculator above to find your exact BMI instantly, or continue reading to see where you sit on the NHS scale.
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.
43kg BMI at Different Heights
Your BMI at 43kg varies significantly by height. Here are realistic examples using standard UK heights:
- At 5ft 2in (157cm): BMI = 17.5 (healthy weight)
- At 5ft 4in (163cm): BMI = 18.1 (healthy weight)
- At 5ft 6in (168cm): BMI = 15.2 (underweight)
- At 5ft 8in (173cm): BMI = 14.4 (underweight)
- At 5ft 10in (178cm): BMI = 13.6 (underweight)
- At 6ft 0in (183cm): BMI = 12.9 (underweight)
The BMI calculator on this page will show your precise BMI once you enter your height. For metric to imperial weight conversions, our weight converter tool helps you switch between kg, stone, and pounds instantly.
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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.
Understanding NHS BMI Categories
The NHS uses standard BMI categories for adults:
- Below 18.5: Underweight
- 18.5–24.9: Healthy weight
- 25.0–29.9: Overweight
- 30.0–34.9: Obese (Class I)
- 35.0+: Obese (Class II or III)
At 43kg, most adults fall into the underweight or healthy weight ranges. However, BMI is a screening tool only — it doesn't account for muscle mass, bone density, or where fat is stored. Your GP can provide personalised guidance about what your BMI means for your individual health.
- 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 43 pounds to kilograms exactly?
43 pounds equals approximately 19.5 kilograms. The precise conversion is 43 lbs × 0.453592 = 19.5 kg. Our weight converter on this page makes this conversion instant and handles stone, pounds, and kg all together.
Is 43kg a healthy weight?
At 43kg, whether you're at a healthy weight depends entirely on your height. Use the BMI calculator above to find your exact BMI. For most adults, 43kg is quite light and may fall into the underweight range unless you're significantly shorter than average.
What's the difference between kg and stone in UK measurements?
The UK uses both metric (kg) and imperial (stone and pounds) measurements. One stone equals 6.35kg, or 14 pounds. So 43kg equals approximately 6 stone 11 pounds. The weight converter on this page switches between all three instantly.
Can I use BMI to determine if I need to gain weight?
BMI is a useful screening tool but has limitations. If your BMI is below 18.5, speak to your GP about whether weight gain is appropriate for you. Factors like muscle mass, age, and overall health matter more than BMI alone.
Where can I find my healthy weight range for my height?
Your GP can advise on your healthy weight range, which varies by height, age, and health status. The BMI calculator on this page shows the healthy weight range for your height instantly — just enter your measurements to see it.
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.