Free Tool — No Upload Required

BMI Calculator

Compute your Body Mass Index, BMR, TDEE, body fat percentage, and lean body mass. Interactive gauge, history tracking, printable reports. All private in your browser.

Personal Details
Body Measurements
Activity Level (for TDEE)
Enter your details and click Calculate to see results.
Measurement History

Your saved BMI measurements are stored locally in your browser.

No history yet.
Ready
Enter your details to calculate BMI
Why Use AFFLIGO?
Comprehensive Analysis
BMI, Oxford BMI, BMR, TDEE, body fat %, lean mass, BMI Prime — all in one place.
History Tracking
Save measurements locally and track your progress over time.
Printable Report
Generate a clean report for your records or doctor visits.
Read the Guide
How to Calculate BMI
Step-by-step guide for BMI, BMR, TDEE, and body fat estimation.
Read Guide →
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BMI Categories

Underweight — < 18.5

Normal — 18.5 — 24.9

Overweight — 25 — 29.9

Obese — 30 +

How It Works

Enter Details
Input your gender, age, height, weight, and activity level.
Calculate
Click Calculate to get BMI, BMR, TDEE, body fat %, and more.
Save & Track
Save to history, print a report, or copy results to clipboard.

Frequently Asked Questions

What is BMI and how is it calculated?

BMI (Body Mass Index) is calculated by dividing your weight in kilograms by the square of your height in meters. It's a quick screening tool to categorize you as underweight, normal weight, overweight, or obese.

How accurate is the body fat percentage estimate?

The body fat estimate uses the Deurenberg formula, which is a reasonable approximation but not as accurate as DEXA scans or hydrostatic weighing. It provides a general guide for tracking trends over time.

Is my data stored on any server?

No. All calculations happen in your browser. History is saved in your browser's localStorage and never leaves your device. 100% private.

What is BMI Prime?

BMI Prime is your BMI divided by 25 (the upper limit of normal weight). A value of 1.0 means you're at the upper boundary. Below 0.75 is significantly underweight, and above 1.2 is significantly overweight.

Can I track my BMI over time?

Yes! Use the Save to History button after each calculation. All entries are stored locally and can be viewed in the History tab. You can also clear individual entries or the entire history.