Free Health & Fitness Calculators

A growing library of accurate, easy-to-use calculators built to help you understand your body and train smarter.

All Calculators

Each tool uses the formulas trusted by clinicians and coaches. No signup, no email — just enter your details and get accurate results.

Get your daily protein, carb, and fat targets for losing fat, maintaining, or building muscle.

Find your daily protein target, how to split it across meals, and what it looks like in real food.

Check your Body Mass Index, healthy weight range, and what your score means for your health.

Estimate your body fat percentage using the U.S. Navy, U.S. Army, or BMI-based formulas.

Calculate your lean body mass, fat mass, and lean mass index using four proven methods.

Find your max heart rate and personalized training zones using Tanaka, 220-age, Gulati, or Karvonen.

Estimate calories burned for 37 activities based on your weight and how long you train.

Find how much water to drink daily based on your weight, activity level, and climate.