BMI Calculator – Accurate & Easy Body Mass Index Tool

BMI & BMI Prime Calculator

Calculate BMI, BMI Prime, category, and healthy weight range.

Unit system

Height

Weight

Height

Weight

BMI

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BMI Prime

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BMI = weight (kg) ÷ height² (m²).
BMI Prime = BMI ÷ 25.
Adult categories used: <18.5 underweight, 18.5–<25 normal, 25–<30 overweight, 30+ obesity classes.

Estimate calories to gain weight safely. Set your goal rate and get daily surplus calories and weekly gain estimates.

Waist-to-Height & Waist-to-Hip Ratio Calculator helps you measure WHtR and WHR, understand body fat distribution, and view easy results fast.

Convert mcg to IU (and IU to mcg) for common vitamins. Choose vitamin type for accurate unit conversion.

Calculate maintenance calories (TDEE) from BMR and activity. Know how many calories to maintain your current weight.

Use the Harris-Benedict equation to calculate BMR and estimate daily calories (TDEE) based on activity level.

Calculate BMR using the Mifflin-St Jeor equation. Get your daily calorie needs based on age, height, weight, and sex.

Calculate your daily calories (TDEE) with US goals like lose 1 lb/week or gain 0.5 lb/week. See weekly change and targets instantly.

Free ideal weight calculator using the Devine formula. Enter your height and weight to find your ideal body weight in kg and lb instantly.

Child Height Predictor to estimate a child’s adult height using parent height, age, sex, weight, and current height in one easy calculator.