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 8.9 kg in Stone?
8.9 kg is equal to 1 stone and 6.1 pounds (or approximately 1.4 stone). This is a relatively light weight for UK adults. To convert kilograms to stone using the standard conversion, divide the kilogram value by 6.35029. Our free weight converter above lets you switch instantly between kg, stone, and lbs — useful for understanding weight across different measurements. Whether you're tracking health metrics, monitoring a child's weight, or simply curious about unit conversions, knowing how to convert weight measurements is practical and straightforward.
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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.
8.9 kg to Stone Conversion Table
To convert 8.9 kg to stone, divide by 6.35029. Here's the exact calculation: 8.9 ÷ 6.35029 = 1.4 stone (or 1 stone 6.1 lbs). Below is a conversion table showing nearby kilogram values in both stone and pounds format:
- 8.0 kg = 1.26 stone (1 stone 3.6 lbs)
- 8.5 kg = 1.34 stone (1 stone 4.8 lbs)
- 8.9 kg = 1.4 stone (1 stone 6.1 lbs)
- 9.0 kg = 1.42 stone (1 stone 6.3 lbs)
- 9.5 kg = 1.50 stone (1 stone 7.5 lbs)
- 10.0 kg = 1.58 stone (1 stone 8.1 lbs)
- 10.5 kg = 1.65 stone (1 stone 9.3 lbs)
This conversion follows the exact kilogram to stone conversion formula used across UK health services. Use our weight converter tool on this page to convert any weight instantly between metric and imperial measurements.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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.
BMI Context at 8.9 kg
At 8.9 kg, your BMI depends entirely on height. This is a very light weight for most UK adults — comparable to young children or early adolescents. For example, at average UK adult heights:
- At 150 cm (4ft 11in): BMI = 3.96 (severely underweight)
- At 160 cm (5ft 3in): BMI = 3.48 (severely underweight)
- At 170 cm (5ft 7in): BMI = 3.08 (severely underweight)
- At 180 cm (5ft 11in): BMI = 2.75 (severely underweight)
Calculate your personal BMI using our free BMI calculator above to understand your own weight status and whether your weight falls within a healthy range for your specific height and age.
- 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 8.9 kg to stone manually?
Divide 8.9 by 6.35029. The answer is approximately 1.4 stone, or 1 stone and 6.1 pounds. For quick conversions, use the weight converter tool on this page — it's instant and accurate for any kilogram value.
Is 8.9 kg a healthy weight for an adult?
8.9 kg is extremely light for an adult human. It's typical weight for a young child or early adolescent, not an adult. If you're an adult at this weight, speak to your GP about whether it's healthy for your age, height, and health status. BMI alone doesn't tell the full story.
What's the difference between stone and pounds?
One stone equals exactly 14 pounds. So 1 stone 6.1 lbs means 1 stone plus 6.1 additional pounds, totalling about 20.1 lbs. The UK uses stone and pounds together as the traditional weight measurement, while kilograms are used in clinical settings. Our converter handles all three units.
How do I check if 8.9 kg is healthy for my height?
Use our free BMI calculator above by entering your weight (8.9 kg) and your height. The calculator will show your BMI category according to NHS guidelines. Then speak to your GP if you have concerns — they can give personalised advice based on your health history.
Can I use this conversion for any weight?
Yes. The formula (divide kilograms by 6.35029 to get stone) works for any weight. Try our weight converter tool for gradual improvement with any kg, stone, or lbs value. It's useful for understanding NHS health data, tracking weight changes, or comparing measurements across countries.
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.