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 45kg In Stones?
45 kilograms is equal to 7 stone and 1.6 pounds using standard UK weight conversion. To convert 45kg to stone, divide by 6.35 — the exact conversion factor between kilograms and stone. This weight falls within the healthy range for many adults, though what constitutes a healthy weight depends on your height and overall health. Use our free weight converter above to switch between kg, stone, and pounds instantly, or calculate your personal BMI with our free BMI calculator to understand where this weight sits for your individual height.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
45kg in Stone — The Exact Conversion
45kg = 7 stone 1.6 lbs (or 7st 1.6lbs)
The conversion formula is straightforward: divide kilograms by 6.35029 to get stone. Using this method, 45 ÷ 6.35 = 7.1 stone. To convert the decimal to stones and pounds, multiply the decimal (0.1) by 14 (the number of pounds in one stone): 0.1 × 14 = 1.6 pounds.
- 45kg in kilograms: 45.0 kg
- 45kg in stone: 7 stone 1.6 lbs
- 45kg in pounds: 99.2 lbs
This conversion is used across the UK for personal weight measurements, clothing sizes, and health assessments. The NHS uses kilograms for clinical purposes, but most UK adults find stone and pounds more intuitive for understanding their own body weight.
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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.
Is 45kg a Healthy Weight? BMI and UK Health Context
Whether 45kg is a healthy weight depends entirely on your height. According to NHS guidelines, a healthy BMI falls between 18.5 and 24.9 for most adults. For someone 160cm (5ft 3in) tall, 45kg gives a BMI of approximately 17.6, which is below the healthy range. For someone 175cm (5ft 9in) tall, the same weight gives a BMI of 14.7, which is underweight. Calculate your personal BMI using our free tool above to see where 45kg sits for your specific height and age. If you're concerned about whether your weight is appropriate for your health, your GP can provide personalised guidance based on your individual circumstances, medical history, and overall 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 45kg to stone manually?
Divide 45 by 6.35 to get 7.1 stone. Then multiply the decimal (0.1) by 14 to convert to pounds: 7 stone 1.6 lbs. Our free weight converter above does this instantly for any weight.
Is 45kg underweight?
It depends on height. At 160cm, 45kg is slightly underweight (BMI 17.6). At 175cm, it's significantly underweight (BMI 14.7). Use our BMI calculator to check your personal BMI — it accounts for both weight and height.
What's the average UK adult weight?
UK adult men average approximately 85.7kg (13st 7lbs), and women average approximately 71.6kg (11st 3lbs). However, healthy weight varies widely based on height, muscle mass, and individual health factors.
How do I know if my weight is healthy?
Your GP can assess your health holistically using BMI, waist circumference, blood pressure, and other health markers. NHS healthy weight guidance recommends a BMI of 18.5–24.9 for most adults, with lower thresholds for some ethnic groups.
Can I use this weight converter for other measurements?
Yes — our free weight converter on this page converts between kilograms, stone, and pounds instantly. You can also use it to calculate BMI once you enter your height alongside any weight.
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.