Health and Fitness

Calculate BMI, calories, body fat, macros, heart rate zones, ideal weight, and running pace.

12 tools

BMI Calculator

Calculate your Body Mass Index with a visual scale showing underweight, normal, overweight, and obese categories.

Health and Fitness

Calorie Calculator

Calculate your Total Daily Energy Expenditure (TDEE) and daily calorie needs using the Mifflin-St Jeor formula.

Health and Fitness

Body Fat Percentage Calculator

Estimate your body fat percentage using the US Navy method with neck, waist, and hip circumference measurements.

Health and Fitness

Water Intake Calculator

Find out how much water you should drink daily based on your weight, activity level, and climate conditions.

Health and Fitness

Heart Rate Zone Calculator

Calculate your personalized training heart rate zones using the Karvonen method with resting heart rate.

Health and Fitness

Macro Calculator

Calculate your daily protein, carbohydrate, and fat targets based on your calorie needs and fitness goals.

Health and Fitness

Ideal Weight Calculator

Find your ideal body weight range using multiple established formulas including Devine, Robinson, and Hamwi.

Health and Fitness

Pace Calculator

Calculate your running pace, finish time, or distance for any race. Supports min/km and min/mi formats.

Health and Fitness

Pregnancy Due Date Calculator

Estimate your baby's due date from your last period or conception date, plus your current week and trimester.

Health and Fitness

Blood Alcohol Content Estimator

Estimate your blood alcohol concentration (BAC) based on drinks consumed, body weight, sex, and time elapsed.

Health and Fitness

Sleep Cycle Calculator

Find the best times to wake up or go to sleep based on 90-minute sleep cycles to feel more refreshed.

Health and Fitness

One Rep Max Calculator

Estimate your one-rep max for any lift using weight and reps performed. Includes percentage-based training loads.

Health and Fitness

How Our Health Calculators Work

Each calculator here is built on a published formula. The BMI Calculator divides your weight by your height squared. The Calorie Calculator uses the Mifflin-St Jeor equation to estimate how many calories you burn in a day. The Body Fat Percentage Calculator uses the US Navy method, which needs only a tape measure.

These results are estimates, not a diagnosis. The formulas are based on averages, so your real numbers can differ. The Blood Alcohol Content Estimator is a good example. No estimate can tell you that you are safe to drive. The Pregnancy Due Date Calculator counts 280 days from the first day of your last period, adjusted for cycle length. Even so, only a small share of babies arrive on their due date.

For training, the Heart Rate Zone Calculator uses your resting heart rate to set zones (the Karvonen method). The Pace Calculator links distance, finish time and pace per kilometer or mile. Talk to a doctor before you make big changes to your diet, exercise or medication.