BMI Calculator

Free BMI Calculator — Body Mass Index

A simple BMI (Body Mass Index) calculator that helps you understand your weight category based on your height and weight.

Enter your height and weight using either metric (kilograms and centimeters) or imperial (pounds and inches) units. Tuttilo calculates your BMI instantly by dividing your weight by the square of your height. Your result appears immediately with a color-coded indicator showing which category you fall into: underweight, normal weight, overweight, or obese. All calculations happen directly in your browser, keeping your health data completely private without any server storage.

Health professionals use this tool for initial patient assessments during routine checkups. Fitness trainers track client progress by calculating BMI at the start and end of programs. Individuals preparing for medical procedures often need to check if they meet specific BMI requirements. Parents monitor their children's growth patterns by comparing BMI results against age-specific percentile charts provided by pediatricians.

Remember that BMI doesn't account for muscle mass, so athletes and bodybuilders may show elevated readings despite being healthy. For the most accurate tracking, measure yourself at the same time of day, preferably in the morning before eating. Keep a record of your BMI over time rather than focusing on a single measurement. If your result falls outside the normal range, consult a healthcare provider who can assess additional factors like body composition and overall health markers.

All processing happens directly in your browser. Your files never leave your device — no server uploads, no cloud storage, no data retention. The tool works offline once loaded, requires no registration, and is completely free with no usage limits.