Health & Fitness Calculators
Free health and fitness calculators for BMI, body fat, calories, ideal weight, heart-rate zones, and hydration. Estimate your numbers in seconds — for education, not medical advice.
16 free health & fitness calculators
BMI Calculator
Calculate your Body Mass Index (BMI) from your height and weight. See where you fall on the BMI scale, learn your category, and what your number means.
Calorie Calculator
Calculate how many calories you need per day based on your age, weight, height, and activity level. Find your TDEE for weight loss, maintenance, or gain.
Body Fat Calculator
Calculate your body fat percentage using the trusted U.S. Navy method. Enter a few simple measurements to get an accurate estimate of your body composition.
Sleep Calculator
Calculate the best time to fall asleep or wake up based on 90-minute sleep cycles. Wake up feeling refreshed by timing your rest to complete full cycles.
Pace Calculator
Calculate your running pace, finish time, or distance for any race. Perfect for runners in training, find your exact pace per mile or per kilometer fast.
Water Intake Calculator
Calculate how much water you should drink each day based on your weight, activity level, and climate. Get personalized hydration tips to stay healthy.
Ideal Weight Calculator
Calculate your ideal body weight from your height and gender using several trusted medical formulas. Find your healthy target weight range in lbs or kg.
Heart Rate Zone Calculator
Calculate your target heart rate zones for smarter exercise. Find your fat-burning, cardio, and peak zones based on your age and resting heart rate now.
Sunburn Calculator
Sunburn calculator: find how long until you burn from the UV index, your skin type, and sunscreen SPF. Plan safe sun and tanning time with MED-based estimates.
PM2.5 to Cigarettes Calculator
Convert PM2.5 air pollution into cigarettes per day with the Berkeley Earth formula: about 22 µg/m³ equals 1 cigarette daily, so 880 µg/m³ is roughly 40 a day.
Blood Alcohol Content (BAC) Estimator
Estimate your blood alcohol content (BAC) based on drinks consumed, body weight, and time elapsed. Uses the Widmark formula for educational purposes only.
Burn Off That Donut Calculator
Find out how long you need to exercise to burn off the calories in any food. Enter calories and your weight to see times for walking, running, and cycling.
Junk Food to Exercise Converter
See how much exercise it takes to burn off popular junk foods. Pick pizza, burgers, fries, or donuts and learn how long to walk, run, or cycle to work it off.
Sleep Debt Calculator
Calculate your weekly sleep debt by entering your target hours and actual sleep each day. Get a personalized catch-up plan to recover from lost rest fast.
Bike Size Calculator
Calculate your ideal bike frame size from your inseam and height. Works for road, mountain, and hybrid bikes, with recommended wheel sizes and saddle height.
Pokémon GO Weight Loss Calculator
Calculate calories burned and distance walked playing Pokémon GO. Enter play time and pace to see your workout equivalent and how many eggs you can hatch.