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
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17.6 Pounds to Kg — What's Your BMI?
17.6 pounds converts to exactly 8.0 kilograms. However, whether this weight is healthy for you depends entirely on your height. A person who weighs 8.0 kg at one height may have a very different BMI than someone of a different height. Our free BMI calculator above will show you your exact BMI instantly — just enter your weight and height in either metric or imperial measurements. Once you know your BMI, you can compare it to NHS guidelines to understand where your weight sits health-wise.
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.
BMI at Different Heights for 17.6 Pounds (8.0 kg)
17.6 pounds (8.0 kg) is a very light weight that only makes sense in specific contexts — such as a young child, a very small adult, or in a medical setting. To convert pounds to kg accurately, divide the pound value by 2.20462. At 8.0 kg, your BMI depends entirely on your height:
- At 5 feet 4 inches (163 cm): BMI of 4.8 — far below healthy range
- At 5 feet 8 inches (173 cm): BMI of 4.3 — far below healthy range
- At 6 feet 0 inches (183 cm): BMI of 3.8 — far below healthy range
At any adult height, 8.0 kg would be dangerously underweight. The healthy weight for an adult of this height would typically be several times higher. To convert kilograms to stone for comparison, remember that 8.0 kg equals only 1 stone 3.8 pounds. Use our weight converter above to check conversions between kg, stone, and pounds 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.
NHS BMI Categories and What They Mean
The NHS defines healthy BMI for most UK adults as between 18.5 and 24.9. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the healthy range begins at 18.5 and ends at 22.9 due to higher health risks at lower BMI levels. A BMI below 18.5 is classified as underweight and may indicate malnutrition or underlying health issues that require GP assessment.
It's important to understand that BMI has limitations — it doesn't distinguish between muscle and fat, and doesn't account for where fat is stored around the body. However, for screening purposes, BMI remains a useful starting point. If your BMI is significantly below, at, or above the healthy range, your GP can provide personalised advice about what this means for your individual health and whether any intervention is needed.
- 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 17.6 pounds to kg?
Divide 17.6 by 2.20462 to get 8.0 kg. Our free weight converter above makes this instant — enter the value in pounds and select kilograms, and you'll see the conversion immediately. You can also convert between stone, pounds, and kg using the same tool.
What BMI does 8.0 kg give at different heights?
At 5ft 4in (163cm): BMI 4.8. At 5ft 8in (173cm): BMI 4.3. At 6ft (183cm): BMI 3.8. All of these are dangerously underweight. Use our free BMI calculator above to enter your exact height and weight for your personal BMI result.
Is 8.0 kg a healthy weight for an adult?
No. 8.0 kg (17.6 lbs or 1 stone 3.8 lbs) is dangerously underweight for any adult. This weight is only normal for very young children. If you or someone you know weighs this little, GP assessment is essential to rule out underlying health issues.
What does the NHS say about healthy weight?
The NHS recommends a BMI between 18.5 and 24.9 for most adults, with slightly lower thresholds (18.5–22.9) for South Asian, Chinese, Black African, or Black Caribbean adults. Your GP can discuss your individual healthy weight range based on your height, age, and medical history.
What are the limitations of BMI?
BMI doesn't account for muscle mass, bone density, or where fat is stored around the body. Athletes may have high BMI due to muscle. BMI is less accurate for children, elderly people, and pregnant women. It's a useful screening tool but should never replace personalised medical advice from your GP.
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.