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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What BMI Is 15.6 Kg In Pounds?
15.6 kilograms equals 34.4 pounds (or 34 pounds 6.4 ounces) using the standard metric to imperial weight conversion. However, the BMI this weight gives depends entirely on your height — the same weight can represent very different health contexts at different heights. Below, we show you what BMI 15.6 kg produces at common UK adult heights and where each falls on NHS BMI categories. Use our free BMI calculator above to find your exact personal BMI instantly.
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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.
15.6 Kg BMI At Different Heights
At 15.6 kg, here's what your BMI would be at various heights, and which NHS category it falls into:
- 150 cm (4ft 11in): BMI 6.9 — Severely underweight
- 160 cm (5ft 3in): BMI 6.1 — Severely underweight
- 170 cm (5ft 7in): BMI 5.4 — Severely underweight
- 175 cm (5ft 9in): BMI 5.1 — Severely underweight
- 180 cm (5ft 11in): BMI 4.8 — Severely underweight
- 190 cm (6ft 3in): BMI 4.3 — Severely underweight
At 15.6 kg, regardless of height, the BMI is well below the NHS healthy weight range of 18.5–24.9. This weight would be appropriate for a young child or infant, not an adult. If you're calculating weight for an adult, please check your measurement — our free weight converter can help you switch between kilograms, stone, and pounds.
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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 BMI Categories And Healthy Weight
The NHS BMI chart defines healthy weight for adults as a BMI between 18.5 and 24.9. A BMI below 18.5 indicates being underweight, which can increase health risks including weakened immunity, bone loss, and nutritional deficiencies. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends slightly different thresholds — a healthy BMI starts at 18.5 and extends to 22.9. Remember that BMI is a screening tool and has limitations: it doesn't account for muscle mass, bone density, or where fat is stored on the body. Your GP can provide personalised guidance about what a healthy weight means for you specifically.
- 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 many pounds is 15.6 kg?
15.6 kilograms equals 34.4 pounds exactly. To convert kg to pounds, multiply by 2.20462. You can also use the weight converter on this page to switch between kilograms, stone, pounds, and other units instantly.
Is 15.6 kg a healthy weight for an adult?
At 15.6 kg, the BMI would be dangerously low for any adult height — this weight is typical for a young child or infant, not an adult. If calculating adult weight, please verify your measurement. For adults, the NHS recommends a BMI between 18.5 and 24.9, which typically corresponds to much higher weights depending on height.
What height would make 15.6 kg a healthy weight?
15.6 kg cannot produce a healthy adult BMI at any realistic height. An adult would need to be extremely short (under 100 cm) for this weight to be appropriate, which is outside normal human adult height range. If you're calculating for a child, use the NHS Growth Reference Charts instead — adult BMI categories don't apply to children.
How do I convert 15.6 kg to stone and pounds?
15.6 kg equals 2 stone 6.4 pounds (or 2st 6.4lbs). Use the formula: divide kg by 6.35029 to get stone. Our weight converter above makes this instant — just enter your weight and it displays automatically in stone, pounds, and kilograms.
Should I be concerned if my BMI is very low?
Yes — a BMI below 18.5 in adults is considered underweight and can increase health risks. If your actual adult weight gives a low BMI, speak to your GP about nutrition and health. If you've calculated 15.6 kg in error, please double-check your measurement using our free weight converter to ensure accuracy.
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.