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 43 Kilos in Stone and What Does Your BMI Mean?
43 kilograms is equivalent to 6 stone and 10 pounds in UK measurements. However, your BMI (and what it means for your health) depends entirely on your height. At different heights, 43kg can give you a healthy BMI or indicate you may be underweight according to NHS guidelines. Use our free BMI calculator above to find your exact BMI, or read on to see how 43kg converts across different heights and what the NHS categories mean for your health.
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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 — NHS Categories
Your BMI at 43kg varies significantly based on your height. Here's how 43kg converts and what NHS category it falls into:
- At 150cm (4ft 11in): BMI = 19.1 — Healthy weight range
- At 155cm (5ft 1in): BMI = 17.9 — Healthy weight range
- At 160cm (5ft 3in): BMI = 16.8 — Underweight
- At 165cm (5ft 5in): BMI = 15.8 — Underweight
- At 170cm (5ft 7in): BMI = 14.9 — Underweight
- At 175cm (5ft 9in): BMI = 14.0 — Underweight
At 43kg, most adults will have a BMI below the healthy range unless you're relatively short. If your height is close to 150cm or shorter, 43kg may fall within the healthy 18.5–24.9 range. Use the BMI calculator on this page to find your exact BMI and height.
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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.
Understanding NHS BMI Categories and Limitations
The NHS categorises adult BMI as follows: underweight (below 18.5), healthy weight (18.5–24.9), overweight (25.0–29.9), and obese (30 and above). However, BMI has important limitations. It doesn't distinguish between muscle and fat — athletes may have a high BMI despite low body fat. It also doesn't account for where fat is stored, which matters for health. If you're concerned about whether 43kg is healthy for you, speak to your GP, who can assess your individual health picture alongside other factors like fitness, medical history, and family risk factors.
- 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 kilos to stone and pounds?
To convert 43kg to stone, divide by 6.35029. This gives 6.78 stone, which equals 6 stone and 10.9 pounds (approximately 6st 10.9lbs). Use our free weight converter on this page to switch between kg, stone, and lbs instantly for any weight value.
Is 43kg a healthy weight for an adult?
It depends on your height. At 43kg, you may be underweight or in the healthy range depending on how tall you are. For example, at 150cm you'd have a healthy BMI, but at 170cm you'd be underweight. Use our BMI calculator above to check your personal BMI and see what the NHS recommends for your height.
What counts as underweight according to the NHS?
The NHS defines underweight as a BMI below 18.5. Being consistently underweight can affect bone health, immunity, and energy levels. If you're underweight and concerned, your GP can assess whether you need support with nutrition or explore any underlying health factors.
Can I use BMI alone to assess my health?
BMI is a useful screening tool but has limits. It doesn't account for muscle mass, bone density, or where fat is stored. For a complete picture of your health, your GP may also consider your waist circumference, fitness level, and medical history.
How accurate is the kg to stone conversion?
The kilogram to stone conversion is mathematically precise: 1 stone equals exactly 6.35029kg. So 43kg ÷ 6.35029 = 6.78 stone. Our weight converter uses these exact figures to give you accurate results every time.
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.