BMI
Calculator
Calculate your Body Mass Index instantly. Find out if you're in a healthy weight range with our free, science-based BMI calculator.
How BMI Works
A simple formula to understand your body composition
Enter Your Stats
Input your weight and height. Works with both metric (kg/cm) and imperial (lbs/inches) units.
Instant Calculation
Your BMI is calculated instantly using the standard formula: weight(kg) / height(m)².
Know Your Category
See your BMI category with a visual gauge and understand what your number means for your health.
Why Track Your BMI?
Understanding your body is the first step to better health
Health Awareness
BMI helps you understand if your weight is in a healthy range and identify potential health risks early.
Goal Setting
Use your BMI to set realistic weight goals and track progress toward a healthier body composition.
Quick Assessment
Get an instant snapshot of your weight status without expensive equipment or doctor visits.
Track Over Time
Monitor your BMI regularly to see trends and ensure your diet and exercise plan is working.
Paired with AI Tracking
Combine your BMI insights with kCal AI's calorie tracking for a complete health management solution.
Free & Accessible
No sign-ups, no downloads needed. Use our free BMI calculator anytime, anywhere, on any device.
Understanding Your BMI
Body Mass Index (BMI) is a widely used metric that provides a quick assessment of body weight relative to height. While not perfect, it serves as a useful starting point for understanding your health status.
The formula is simple: BMI = weight(kg) ÷ height(m)². For imperial units, the formula includes a conversion factor: BMI = (weight(lbs) × 703) ÷ height(in)².
Limitations to Keep in Mind
- Muscle vs Fat: BMI doesn't distinguish between muscle and fat mass. Athletes may show as overweight despite being very fit.
- Age & Gender: BMI categories are the same for all adults but may not be equally applicable across all age groups.
- Body Composition: For a more complete picture, combine BMI with waist circumference and body fat percentage.
- Track your nutrition with kCal AI to maintain a healthy BMI through accurate calorie monitoring.
Frequently Asked Questions
Common questions about BMI and body weight
Track Your Calories with AI Precision
Download kCal AI for free and start tracking your meals instantly. Available on iOS and Android.