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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11.7 kg in Lbs — Is This Weight Healthy?
11.7 kilograms equals 25.8 pounds. Whether this weight is healthy depends entirely on your height — there's no single "healthy weight" that applies to everyone. Our free BMI calculator above can tell you instantly whether 11.7 kg sits within a healthy range for your specific height and age. In this guide, we'll show you how to interpret your weight using NHS guidelines, explore healthy weight ranges across different heights, and explain what steps to take if you're concerned about your health.
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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.
Healthy Weight Ranges by Height
At 11.7 kg, you're looking at a very light body weight. To understand whether this is healthy for you, we need to factor in your height. Here are three concrete examples using NHS BMI guidelines:
- 5ft 0in (152cm): At this height, 11.7 kg gives a BMI of 5.1 (severely underweight). Healthy range is 45–61 kg.
- 5ft 6in (168cm): At this height, 11.7 kg gives a BMI of 4.1 (severely underweight). Healthy range is 52–70 kg.
- 6ft 0in (183cm): At this height, 11.7 kg gives a BMI of 3.5 (severely underweight). Healthy range is 61–82 kg.
As you can see, 11.7 kg is significantly below the healthy weight range for any adult height. The NHS recommends a healthy BMI between 18.5 and 24.9. Use our weight converter above to explore how kilos to stone conversions work, then calculate your personal BMI to see where you currently stand.
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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 Guidance and When to Seek Help
If you weigh 11.7 kg as an adult, this is a medical concern that requires urgent GP attention. Severe underweight can indicate malnutrition, eating disorders, or underlying health conditions. Your GP can assess your health holistically and refer you to appropriate support.
Healthy weight isn't just about numbers — it's about how you feel, your energy levels, and your overall wellbeing. Waist circumference also matters: NHS guidance suggests a waist above 94cm (men) or 80cm (women) increases health risk, though this applies to overweight individuals. If you're underweight, your focus should be on reaching a healthy weight range safely with professional guidance.
- 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 11.7 kg to lbs accurately?
11.7 kg multiplied by 2.20462 equals 25.8 lbs (or 25 lbs 13 oz). Use our free weight converter above to switch between kilograms, stone, and pounds instantly. UK measurements matter, so our tool includes stone conversions too.
What's the healthy weight range for my height?
Healthy weight depends on height and age. Use our free BMI calculator above by entering your height and current weight. The NHS recommends a BMI between 18.5–24.9 for most adults. For South Asian, Chinese, Black African, or Black Caribbean adults, the healthy range starts at BMI 18.5–22.9.
Is 11.7 kg a realistic body weight for an adult?
11.7 kg is significantly underweight for any adult and would be a serious health concern. This weight might be healthy only for a small child. If you or someone you know weighs this little, please contact your GP immediately for professional assessment.
Should I be worried if I weigh less than the healthy range?
Yes — being significantly underweight can indicate malnutrition, eating disorders, or medical conditions. Your GP can investigate and provide appropriate support. Speak to your healthcare provider about safe ways to reach a healthy weight if needed.
How do I use stone measurements alongside kg conversions?
11.7 kg converts to approximately 1 stone 13 lbs. Our weight converter above lets you instantly switch between metric (kg) and imperial (stone and pounds) measurements, which is standard in UK health contexts.
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.