Health & Fitness Calculators
BMI, calories, macros, due dates, and more · 19 calculators
Body Composition5
BMI Calculator
Calculate your Body Mass Index (BMI) and see what it means for your health. Supports both imperial and metric units.
Body Fat Calculator
Estimate your body fat percentage with the U.S. Navy method using height, neck, waist, and hip measurements. See your body fat category and lean mass.
Ideal Weight Calculator
Find your ideal body weight using the Devine, Robinson, Miller, and Hamwi formulas, based on your height and sex. Compare all four estimates side by side.
Lean Body Mass Calculator
Estimate your lean body mass (LBM) — total weight minus fat — using the Boer and James formulas from your height, weight, and sex.
Waist-to-Hip Ratio Calculator
Calculate your waist-to-hip ratio (WHR) and see your health-risk category by sex, based on World Health Organization thresholds.
Calories & Diet6
Calorie Calculator
Calculate your daily calorie needs based on age, weight, height, activity level, and goal. Includes macronutrient breakdown.
TDEE Calculator
Calculate your Total Daily Energy Expenditure (TDEE) — the maintenance calories you burn each day — using the Mifflin-St Jeor equation and your activity level.
BMR Calculator
Calculate your Basal Metabolic Rate (BMR) — the calories your body burns at rest — using the Mifflin-St Jeor and Harris-Benedict equations.
Macro Calculator
Turn your daily calories into grams of protein, carbs, and fat. Pick a goal and macro ratio to get a personalized macronutrient breakdown for your diet.
Protein Intake Calculator
Calculate how much protein you should eat per day in grams, based on your weight, activity level, and goal — from general health to building muscle.
Water Intake Calculator
Find out how much water you should drink each day based on your body weight and activity level. Get your daily target in ounces, liters, and cups.
Fitness & Rest5
Running Pace Calculator
Calculate your running pace, speed, and finish time. Enter a distance and time to get pace per mile and km, or predict a finish time from a target pace.
One Rep Max Calculator
Estimate your one-rep max (1RM) from the weight and reps you lifted using the Epley and Brzycki formulas. Includes a training percentage table from 60–95%.
Calories Burned Calculator
Estimate the calories you burn during any activity using MET values, your body weight, and the duration. Covers running, walking, cycling, weights, and more.
Target Heart Rate Calculator
Find your target heart rate training zones using the Karvonen (heart-rate reserve) method and percentage of max heart rate, based on your age and resting HR.
Sleep Calculator
Find the best time to go to bed or wake up based on 90-minute sleep cycles, so you wake up between cycles feeling more rested.
Pregnancy & Health3
Pregnancy Due Date Calculator
Calculate your pregnancy due date, trimester dates, and key milestones from your last menstrual period or conception date.
Ovulation Calculator
Estimate your most fertile days and ovulation date from the first day of your last period and your average cycle length. See your fertile window and next period.
Blood Alcohol Content (BAC) Calculator
Estimate your blood alcohol content (BAC) with the Widmark formula from the number of drinks, your weight, sex, and time elapsed. For education only — never drink and drive.