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
Calculator for kg — Convert, Calculate, and Understand Your Weight
A calculator for kg helps you convert kilograms to UK measurements, calculate your BMI, and understand what your weight means for your health. Whether you need to convert 70kg to stone, check your BMI, or find your healthy weight range, our free kg calculator and weight converter make it simple. Using NHS guidance and UK health standards, you can get instant answers to your weight-related questions in measurements that make sense to you.
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.
What Can You Calculate With a kg Calculator?
A kg calculator serves multiple purposes for UK health tracking. Most commonly, it converts kilograms to stone and pounds — the measurements most UK adults use daily. Our free weight converter lets you switch instantly between kg, stone, and lbs without a UK pharmacy maths.
- Weight conversion: Convert any kilogram value to stone and pounds (e.g. 70kg = 11 stone 0.1lbs)
- BMI calculation: Use our BMI calculator to find your BMI instantly by entering your weight in kg and height in cm or feet/inches
- Healthy weight range: Discover what weight range is healthy for your height according to NHS guidelines
- Health context: Understand whether your weight falls into underweight, healthy, overweight, or obese categories
For adults of South Asian, Chinese, Black African, or Black Caribbean backgrounds, NHS guidance recommends lower BMI thresholds, which a good kg calculator should reflect.
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.
Using a kg Calculator for Weight Management
A kg calculator becomes especially useful when you're tracking weight management progress. If you're following a reduced-calorie diet, exercising regularly, or considering prescription weight loss options, converting your weight regularly helps you monitor change. The NHS recommends aiming for a loss of 0.5 to 1 kg per week for sustainable results.
If you're interested in prescription weight loss medication like Mounjaro or Wegovy, our GLP-1 weight loss calculator can help you estimate potential results based on clinical trial data. Combined with regular weight tracking using a kg calculator, you can build a complete picture of your health journey. Always discuss significant weight changes with your GP.
- 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 the easiest way to convert kg to stone?
Divide the kilogram value by 6.35029 to get stone. For example, 70kg ÷ 6.35 = approximately 11 stone. Our free weight converter above does this instantly — just enter your weight in kg and select stone as your output unit.
Why do UK adults use both kg and stone?
The UK uses both metric (kg) and imperial (stone/lbs) measurements. NHS medical records use kg, but most UK people weigh themselves in stone and lbs at home. A kg calculator helps bridge this gap by converting between both systems instantly.
Can a kg calculator tell me if I'm a healthy weight?
Yes. Enter your weight in kg and height, and a kg calculator (like our BMI calculator) will show your BMI and healthy weight range according to NHS guidelines. A healthy BMI is 18.5–24.9 for most adults, though lower thresholds apply for some ethnic groups.
Is there a difference between a kg calculator and a weight converter?
A weight converter focuses on unit conversion (kg to stone). A kg calculator is broader — it converts units AND calculates BMI, healthy ranges, and health context. MyWeightCheck offers both tools integrated together.
Can I use a kg calculator to track weight loss progress?
Yes. Log your weight in kg regularly using a calculator or progress tracker. The NHS recommends losing 0.5–1 kg per week for sustainable results. Track weekly rather than daily for a clearer picture of your actual progress.
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.