BMI Calculator
Calculate your Body Mass Index and find out which weight category you fall into.
Did this tool work for you?
How to use this calculator
Divide your weight in kilograms by the square of your height in metres.
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Enter your weight in kilograms.
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Enter your height in centimetres.
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Your BMI and weight category appear instantly.
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The ideal weight range shows the healthy BMI span for your height.
Frequently asked questions
What is a healthy BMI?
The World Health Organization defines a healthy BMI as between 18.5 and 24.9. Below 18.5 is underweight; 25–29.9 is overweight; 30 and above is obese.
Is BMI accurate for everyone?
BMI is a useful screening tool but has limitations. It does not distinguish between muscle and fat, so athletes with high muscle mass may be incorrectly categorised as overweight. Age and ethnicity can also affect interpretation.
How do I convert pounds and feet to use this calculator?
Divide your weight in pounds by 2.205 to get kilograms. Multiply your height in feet by 30.48 to get centimetres (or inches by 2.54).
What should I do if my BMI is outside the healthy range?
Consult a healthcare professional. BMI is a starting point for conversation — not a diagnosis. A doctor can assess your full health picture.
What is Body Mass Index (BMI)?
How to use the bmi
Use this bmi to your body mass index and find out which weight category you fall into. Enter your values above and get your result in seconds. The tool is free, works on all devices, and keeps your data private — nothing is stored or shared.
How the bmi works
The bmi calculator uses standard formulas used in health tracking, fitness planning, and wellness management. Enter your inputs, and the tool calculates the result instantly in your browser. No server-side processing means your data stays on your device. Results update in real time as you change inputs.
The BMI formula and its origin
Body Mass Index was developed by Belgian mathematician Adolphe Quetelet in the 1830s as a simple way to assess population-level weight status. It remains the most widely used screening metric globally because it requires only weight and height — two measurements anyone can take at home.
BMI categories explained
The WHO defines four main categories: underweight (below 18.5), normal weight (18.5–24.9), overweight (25–29.9), and obese (30 and above). Some health organisations further split obesity into classes I, II, and III for clinical purposes.
Limitations of BMI
BMI does not measure body fat directly, nor does it account for fat distribution, age, sex, or ethnicity. A muscular person can have a high BMI despite low body fat. Asian populations may face higher health risks at lower BMI thresholds. Always combine BMI with other assessments such as waist circumference.
Bmi: how it works
This free tool provides a quick, evidence-based estimate for wellness planning. It uses standard formulas accepted by health professionals worldwide. Enter your measurements for an instant result — always follow up with a qualified practitioner for personal guidance.
Who uses this tool?
Athletes, fitness enthusiasts, nurses, and anyone monitoring their health use it as a starting point for wellness decisions. Share the output with your doctor or dietitian for a professional interpretation.
Learn more from an authoritative source:
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Calorie Calculator
Calculate your daily calorie needs to lose weight, maintain, or gain weight based on your stats and activity.
Body Fat Calculator
Estimate your body fat percentage using the US Navy method with waist, neck, and hip measurements.
Ideal Weight Calculator
Calculate your ideal body weight range using four leading medical formulas — Devine, Robinson, Miller, and Hamwi.
Results are estimates for informational purposes only and do not constitute professional financial, medical, legal, or technical advice. Read full disclaimer →