Fitness & Health Calculators
Track your health and reach your fitness goals with our science-backed calculators. Whether you want to know your BMI, calculate your daily calorie needs, or plan your macros — our tools use clinically validated formulas to give you accurate results.
Body & Weight
View all →BMI Calculator
Body Mass Index with weight category
TDEE Calculator
Total daily energy expenditure by activity level
Body Fat Calculator
Body fat % using the US Navy method
Ideal Weight Calculator
Ideal weight range using 4 clinical formulas
Waist-to-Hip Ratio Calculator
WHR, body shape, and cardiovascular health risk
BMR Calculator
Basal metabolic rate — Mifflin-St Jeor & Harris-Benedict
Lean Body Mass Calculator
Weight minus fat using Boer formula or body fat %
Caloric Deficit Calculator
Daily calorie target and weight loss timeline
Pregnancy Weight Gain Calculator
IOM-recommended weight gain by pre-pregnancy BMI
Body Surface Area Calculator
BSA in m² using 4 validated medical formulas
Army Body Fat Calculator
Military tape-test body fat and AR 600-9 pass limits
Nutrition & Diet
View all →Calorie Calculator
Daily calorie needs based on your goals
Macro Calculator
Daily protein, carb, and fat targets
Carbohydrate Calculator
Daily carb grams from calories and diet split
Water Intake Calculator
Daily water needs by weight and activity
Calories Burned Calculator
Calories burned for 20+ activities
Protein Calculator
Daily protein needs by weight and goal
Keto Calculator
Personalized keto macros: fat, protein, and carbs
Intermittent Fasting Calculator
Eating window, fasting window, and meal schedule
Exercise & Cardio
View all →Heart Rate Calculator
Max HR and training zones by age
Target Heart Rate Calculator
Max HR and training zones (Karvonen) by age
Pace Calculator
Running pace, finish time, or distance
Sleep Calculator
Best time to sleep or wake up
One Rep Max Calculator
Estimate 1RM and training weights from any set
BAC Calculator
Blood alcohol content using Widmark formula
Steps to Miles Calculator
Convert steps to distance and calories burned
VO2 Max Calculator
Estimate aerobic capacity from 3 test methods
Running Calorie Calculator
Calories burned running by weight and distance
Health & Life
View all →Other Categories
Frequently Asked Questions
What formula is used for BMI?
BMI = weight (kg) ÷ height² (m²). This is the standard formula from the World Health Organization. For imperial units, BMI = (weight in lbs × 703) ÷ height² (in²).
What formula is used for calorie calculation?
We use the Mifflin-St Jeor equation, which is considered the most accurate for most adults. It factors in your age, sex, weight, height, and activity level.
Are these health calculators suitable for medical advice?
These calculators are informational tools. Always consult a healthcare professional or registered dietitian for personalized medical or nutritional advice.