Health & Fitness
Track your BMI, daily calories, macros, body fat and more with free health and fitness calculators. Enter your measurements in pounds and feet, with a one-click metric toggle, for instant, science-based estimates.
Popular in this category: BMI Calculator, Calorie Calculator, TDEE Calculator
BMI Calculator
Calculate your body mass index and healthy weight range
Calorie Calculator
Find your daily calorie needs to maintain, lose or gain weight
TDEE Calculator
Calculate your total daily energy expenditure
BMR Calculator
Calculate your basal metabolic rate (calories at rest)
Macro Calculator
Calculate your daily protein, carb and fat targets
Calorie Deficit Calculator
Find the calorie deficit you need to lose weight
Body Fat Calculator
Estimate your body fat percentage (U.S. Navy method)
Ideal Weight Calculator
Find your ideal body weight by height and frame
Protein Calculator
Calculate your daily protein intake needs
Water Intake Calculator
Find how much water you should drink each day
Height Calculator
Predict a child’s adult height from parent heights
Life Expectancy Calculator
Estimate remaining years of life from the SSA actuarial life table
Weight Loss Calculator
Plan your weight loss timeline and calorie target
Bra Size Calculator
Find your correct bra size from measurements
Pace Calculator
Calculate running pace, time and distance
Body Surface Area Calculator
Calculate body surface area (BSA) for dosing
FFMI Calculator
Calculate fat-free mass index
Waist-to-Hip Ratio Calculator
Calculate your waist-to-hip ratio and health risk
Lean Body Mass Calculator
Estimate your lean body mass
Calories Burned Calculator
Estimate calories burned by activity
One Rep Max Calculator
Estimate your one-rep max (1RM) for any lift
Pregnancy Due Date Calculator
Estimate your due date and pregnancy timeline
VO2 Max Calculator
Estimate your VO2 max and cardio fitness
Target Heart Rate Calculator
Find your target heart rate training zones
Army Body Fat Calculator
Calculate body fat using the U.S. Army (ABCP) method
Keto Calculator
Calculate your keto macros (high fat, low carb) for your goal
Carb Calculator
Find your daily carbohydrate target
Weight Gain Calculator
Calculate the calorie surplus to gain weight
Body Shape Calculator
Find your body shape from bust, waist and hip measurements
Body Type Calculator
Estimate your somatotype: ectomorph, mesomorph or endomorph
About health & fitness calculators
Where to start
The BMI Calculator gives a quick weight-status check, while the Calorie Calculator and TDEE Calculator estimate how much you burn each day. From there, the Macro Calculator splits those calories into protein, carbs and fat, and the Body Fat Calculator estimates composition using the U.S. Navy method.
What you need to enter
Most tools need your height, weight, age and sex; activity level is added for calorie and TDEE estimates. Health calculators here are imperial-first (pounds, feet and inches) with a one-click metric switch. Accurate measurements matter most for the body-fat and ideal-weight tools.
A worked example
Someone 5 feet 10 inches (70 inches) tall weighing 175 pounds has a BMI of about 25.1, placing them just into the overweight band that starts at 25. BMI is only a screening number, though - it ignores muscle mass, so a lifter and a sedentary person at the same BMI can have very different body fat, which is where the Body Fat Calculator adds context.
Frequently asked questions
Is BMI accurate for everyone?
BMI is a useful population screen but it does not distinguish muscle from fat. Athletes can read as overweight despite low body fat, so pair BMI with the Body Fat Calculator for a fuller picture.
How are my calorie needs calculated?
The tools use the Mifflin-St Jeor equation to estimate resting metabolic rate, then multiply by an activity factor for total daily energy expenditure. That total is your maintenance calorie level.
Can I switch between pounds and kilograms?
Yes. Every health calculator defaults to U.S. units (pounds, feet and inches) and has a metric toggle for kilograms and centimeters.