Free Fitness & Health Calculators

Quick, accurate and free tools to understand your body. Calculate your protein needs, muscularity, body shape and heart-rate training zones - no sign-up required.

Protein Intake Calculator

Calculate exactly how many grams of protein you need each day based on your body weight, activity level and goal.

FFMI Calculator

Measure your muscularity with the fat-free mass index - and see how close you are to your natural muscle-building ceiling.

Army Body Fat Calculator

Estimate Army body fat percentage from tape measurements and compare your result with age and sex standards.

Body Shape Calculator

Enter your bust, waist and hip measurements to discover your body shape and get tailored styling guidance.

Max Heart Rate Calculator

Estimate your maximum heart rate by age and sex, and get your five personalised training zones.

Body Recomposition Calculator

Get the daily calories and macros to lose fat and build muscle at the same time - body recomposition made simple.

REM Sleep Calculator

Estimate how much REM sleep you get from your sleep duration, bedtime and wake time.

Sleep Debt Calculator

Add your hours slept over the past week to see your accumulated sleep debt and how to recover.

Body Type Quiz

Answer a few quick questions to discover your dominant body type - ectomorph, mesomorph or endomorph.

Target Heart Rate Calculator

Find your personalised target heart rate zones using the Karvonen formula with your age and resting heart rate.

Metabolic Age Calculator

Estimate your metabolic age from your body composition and see if your metabolism is younger than your real age.

Waist-to-Hip Ratio Calculator

Get your waist-to-hip ratio and health-risk category from your waist and hip measurements.

Body Roundness Index Calculator

Estimate your body roundness and visceral fat from your waist and height - a modern alternative to BMI.

REE Calculator

Estimate the calories you burn at rest (REE/RMR) and your total daily energy needs.

Katch-McArdle Calculator

Estimate your BMR and daily calories from your lean body mass using the Katch-McArdle formula.

Fat-Burning Heart Rate Calculator

Find the heart-rate zone where you burn the highest proportion of fat, based on your age.

Yoga Calories Burned Calculator

Estimate the calories you burn in a yoga session based on your weight, style and duration.

Elliptical Calories Burned Calculator

Estimate how many calories you burn on the elliptical based on your weight, intensity and time.

Caffeine Half-Life Calculator

See how much caffeine is left in your system over time and when to stop drinking coffee for better sleep.

Steps to Miles Calculator

Convert steps to miles and kilometers using your height or a custom step length.

Steps to Kilometers Calculator

Convert steps to kilometers and miles using your height or a custom step length.

Creatine Water Intake Calculator

Plan a practical daily hydration range while using creatine, with workout, climate and sweat adjustments.

Creatine Dosage Calculator

Estimate a standard creatine maintenance dose and optional loading-phase schedule from body weight.

Rucking Calorie Calculator

Estimate calories burned while rucking and compare the result with normal walking.

Fiber Intake Calculator

Find your daily fiber target and the gap between your current intake and recommended range.

StairMaster Calorie Calculator

Estimate calories burned on the StairMaster or stair climber from weight, duration and intensity.

Rowing Calorie Calculator

Estimate rowing-machine calories from average watts or a simple effort level.

Cooper Test Calculator

Estimate VO2 max from the distance you can run in 12 minutes.

Rockport Walk Test Calculator

Estimate VO2 max from a one-mile fast walk and finish heart rate.

Running VO2 Max Calculator

Estimate running VO2 max from a recent race or hard time-trial result.

Carb Cycling Calculator

Create high-, moderate- and low-carb macro targets from your body stats, activity and goal.