Health & Fitness
BMI Calculator
Calculate your Body Mass Index with metric or imperial inputs and see your weight category.
Health & Fitness Calculators
Your health numbers matter — but calculating them shouldn't be hard. Our Health & Fitness tools use clinically validated formulas (Mifflin-St Jeor for calories, U.S. Navy method for body fat, Devine/Robinson/Hamwi for ideal weight) to give you accurate estimates. Every tool includes a plain-language explanation of the underlying formula and what your result actually means. Remember: these calculators provide estimates for general information — they're not a substitute for medical advice.
Health & Fitness
BMR Calculator
Calculate your Basal Metabolic Rate using the gold-standard Mifflin-St Jeor equation.
Health & Fitness
Body Fat Calculator
Estimate body fat percentage using the clinically validated U.S. Navy circumference method.
Health & Fitness
Calorie Calculator
Estimate your daily calorie needs based on age, weight, height, sex, and activity level.
Health & Fitness
Due Date Calculator
Calculate your estimated due date by last period or conception date, with weeks pregnant and trimester shown.
Health & Fitness
Ideal Weight Calculator
See your ideal weight from three medical formulas (Devine, Robinson, Hamwi) plus your healthy BMI weight range.
Health & Fitness
Macro Calculator
Calculate your daily protein, carbs, and fat targets based on your calorie needs and fitness goal.
Health & Fitness
One-Rep Max Calculator
Estimate your 1RM for any lift using Epley and Brzycki formulas, plus a training percentage table.
Health & Fitness
Ovulation Calculator
Find your ovulation date and fertile window based on your cycle length and last period, for the next 3 cycles.
Health & Fitness
Period Calculator
Predict your next three period start dates based on your last period and average cycle length. Nothing is stored.
Health & Fitness
Protein Intake Calculator
Calculate your daily protein intake goal based on body weight, activity level, and whether you want to maintain, lose, or build muscle.
Health & Fitness
Running Pace Calculator
Calculate pace, time, or distance for any run. Includes race presets for 5K, 10K, half marathon, and marathon.
Health & Fitness
Sleep Calculator
Find the best bedtime or wake time based on 90-minute sleep cycles and a 15-minute fall-asleep buffer.
Health & Fitness
TDEE Calculator
Calculate your Total Daily Energy Expenditure — the calories needed to maintain your weight.