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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5.9 kg in Stone — BMI Guide for UK Adults
5.9 kg converts to approximately 0 stone 13.0 lbs in UK measurements. However, your BMI depends entirely on your height — the same weight gives a completely different BMI result for a 5ft person versus a 6ft person. This guide shows you what BMI 5.9 kg produces at different heights, and which NHS weight categories apply. Use our free BMI calculator above to find your personal BMI instantly by entering your exact height and weight.
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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.
5.9 kg BMI at Different Heights
At 5.9 kg, your BMI ranges from approximately 28.5 to 44.2 depending on your height. Here are example BMI values at common UK heights:
- 150 cm (4ft 11in): BMI 26.3 — Overweight (NHS category)
- 160 cm (5ft 3in): BMI 23.0 — Healthy weight
- 165 cm (5ft 5in): BMI 21.6 — Healthy weight
- 170 cm (5ft 7in): BMI 20.4 — Healthy weight
- 175 cm (5ft 9in): BMI 19.2 — Healthy weight
- 180 cm (5ft 11in): BMI 18.2 — Healthy weight
To convert kilograms to stone accurately for your height, use the weight converter on this page. Your individual BMI tells you where your weight sits relative to NHS health guidelines.
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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 NHS BMI Categories & Limitations
The NHS BMI categories for UK adults are: Underweight (under 18.5), Healthy weight (18.5–24.9), Overweight (25.0–29.9), and Obese (30.0+). At 5.9 kg, you fall well within the healthy weight range at most adult heights. However, BMI has important limitations: it doesn't distinguish between muscle and fat, doesn't account for where fat is stored (waist measurement matters), and may be less accurate for elderly people or very muscular individuals. Your GP can provide personalised health advice beyond BMI alone. If you're concerned about your weight or health, discuss this with your healthcare provider.
- 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.
What is 5.9 kg in stone and pounds?
5.9 kg converts to 0 stone 13.0 lbs (approximately). In pure pounds, 5.9 kg equals about 13 lbs. Use our free weight converter above to switch between kg, stone, and pounds instantly for any weight value.
Is 5.9 kg a healthy weight?
Whether 5.9 kg is healthy depends on your height and age. For most adults, 5.9 kg produces a healthy BMI at typical heights. Use our BMI calculator to check your personal BMI — it's the best way to see if your weight falls in the NHS healthy range for your height.
What BMI does 5.9 kg give at 170 cm?
At 170 cm (5ft 7in), 5.9 kg gives a BMI of approximately 20.4, which falls in the healthy weight category (18.5–24.9) according to NHS guidelines. This is a healthy BMI result.
How do I use the stone to kg conversion correctly?
To convert stone to kg, multiply the stone value by 6.35029. For reverse conversion (kg to stone), divide by 6.35029. Our free weight converter on this page does this calculation instantly — just enter your weight in either unit and switch between them.
Should I be concerned about my weight at 5.9 kg?
At 5.9 kg, most adults fall in the healthy weight range, though this depends on your height. If you have concerns about your weight or health, speak with your GP. They can assess your individual circumstances and provide personalised guidance beyond BMI alone.
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.