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 45 Kilos in Stones and Pounds?
45 kilograms is equal to 7 stone and 1.2 pounds (or 7st 1lb). This weight in stone and pounds is commonly used in the UK for tracking body weight. However, your BMI at 45kg depends on your height. Use our free BMI calculator above to find your personal BMI, or continue reading to see what 45kg means for health across different heights.
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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.
45kg BMI at Different Heights
45 kilograms produces different BMI values depending on your height. Here are typical BMI results at common UK heights:
- At 5ft 0in (152cm): BMI of 19.5 — healthy weight range
- At 5ft 2in (157cm): BMI of 18.3 — healthy weight range
- At 5ft 4in (163cm): BMI of 16.9 — underweight
- At 5ft 6in (168cm): BMI of 15.9 — underweight
- At 5ft 8in (173cm): BMI of 15.0 — underweight
- At 5ft 10in (178cm): BMI of 14.2 — underweight
According to NHS guidelines, a healthy BMI falls between 18.5 and 24.9. At 45kg, only shorter individuals (around 5ft 0–5ft 2in) fall into the healthy range. Taller individuals would be in the underweight category. Use the weight converter on this page to convert kilos to stone, and the BMI calculator to check your personal BMI instantly.
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.
Understanding BMI Categories and Limitations
The NHS recognises five main BMI categories: underweight (below 18.5), healthy weight (18.5–24.9), overweight (25.0–29.9), obese (30.0–34.9), and severely obese (40.0+). However, BMI has important limitations. It does not distinguish between muscle and fat, so athletes may have high BMI despite low body fat. BMI also does not account for where fat is stored — waist circumference is equally important. Your GP can provide personalised health advice beyond BMI alone. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower BMI thresholds due to higher health risks at the same weight.
- 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 and pounds quickly?
Divide 45 by 6.35029 to get stone. 45kg ÷ 6.35029 = 7.09 stone (7 stone and 1.2 pounds). Alternatively, use our free weight converter above to convert kilograms to stone instantly. This metric to imperial weight conversion is common in the UK.
Is 45kg a healthy weight?
It depends on your height. At 45kg, a BMI of around 18–20 is healthy for someone 5ft 0–5ft 2in tall. For taller individuals, 45kg would be underweight. Use our free BMI calculator on this page to check your personal BMI and see where you fall in the NHS categories.
What does 45kg weigh in stones and lbs?
45kg equals 7 stone and 1.2 pounds. To convert kilos in stone more precisely: multiply the kg figure by 0.157473, or use the weight converter tool above for instant conversions between kg, stone, and lbs.
What is the healthy weight range at my height if I weigh 45kg?
Your healthy weight depends on your height. Use our free BMI calculator to find your healthy weight range in stone and pounds for your specific height. The NHS defines healthy BMI as 18.5–24.9, which translates to different stone weights depending on how tall you are.
How can I track weight changes from 45kg?
Our free progress tracker lets you log your weight in stone, pounds, or kilograms and monitor changes over time. Tracking consistently helps you see whether your weight is moving towards your health goals, whether you're aiming to reach a healthy BMI or manage a specific health condition.
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.