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 16.1kg in Stone and What BMI Does It Give?
16.1kg converts to 2 stone 8.3 pounds in UK measurements. However, your BMI (and what it means for your health) depends entirely on your height. A person weighing 16.1kg at different heights will fall into completely different NHS health categories. Use our free BMI calculator above to find your exact BMI, or read on to see BMI examples at common UK heights.
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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.
16.1kg BMI at Different Heights
Here's what 16.1kg (2 stone 8.3lbs) means in terms of BMI at various heights:
- At 150cm (4ft 11in): BMI of 7.2 — Significantly underweight
- At 160cm (5ft 3in): BMI of 6.3 — Significantly underweight
- At 170cm (5ft 7in): BMI of 5.6 — Significantly underweight
- At 180cm (5ft 11in): BMI of 5.0 — Significantly underweight
- At 190cm (6ft 3in): BMI of 4.5 — Significantly underweight
It's important to note that 16.1kg is an exceptionally low weight for any adult height, and if this represents your actual body weight, speaking with your GP is essential. Use our weight converter to switch between kilograms, 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 Why Weight Context Matters
The NHS defines a healthy BMI range as 18.5 to 24.9 for most adults. At 16.1kg, any adult would fall significantly below this range regardless of height, which is medically concerning. BMI is calculated by dividing weight in kilograms by height in metres squared. Remember that BMI has limitations — it doesn't account for muscle mass, bone density, or overall body composition. If you're genuinely at this weight, your GP can assess your individual health status and provide personalised guidance on nutrition and wellbeing.
- 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 16.1kg to stone accurately?
Divide 16.1 by 6.35029 to get stone. 16.1kg = 2 stone 8.3 pounds. You can also use our free weight converter to switch between kg, stone, and pounds instantly for any weight.
What does it mean if my BMI is below 18.5?
A BMI below 18.5 is classified as underweight by NHS standards. At 16.1kg, this would be the case at all heights. Being significantly underweight can affect bone health, immunity, and energy levels. Speak with your GP for personalised assessment.
Is 16.1kg a healthy weight for adults?
No. 16.1kg is exceptionally low for any adult regardless of height and falls well below the NHS underweight threshold. If this is your actual weight, speaking with your GP or a healthcare professional is important for assessing your health and nutrition needs.
Can I use the BMI calculator to check my own BMI?
Yes. Our free BMI calculator above lets you enter your exact weight in kg or stone, your height, and your age and sex, and instantly shows your BMI and NHS category. It's a helpful starting point for understanding your personal health metrics.
Does muscle mass affect BMI calculations?
Yes. BMI doesn't distinguish between muscle and fat, so athletes or very muscular individuals may have a high BMI despite low body fat. At very low weights like 16.1kg, this is less relevant, but BMI is still best used as a screening tool alongside other health measures.
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.