Health & Fitness Calculators
Free health calculators built on WHO, CDC, and peer-reviewed clinical formulas. BMI, BMR, calories, macros, body fat, hydration, sleep, and more — with context that helps you understand your results.
Start With Your Goal
Not sure which calculator to use first? Find your goal below.
Starting a Weight Loss Journey
Begin with your BMI and TDEE. Then use the Macro Calculator to set nutrition targets and the Calorie Burn Calculator to plan activity.
Building Muscle
Calculate your TDEE for a caloric surplus, then use the Protein Intake Calculator to hit your protein targets. Track progress with Lean Body Mass.
Improving Cardiovascular Fitness
Use the Target Heart Rate Calculator to train in the right zones. Track running progress with the Pace Calculator.
General Health Monitoring
Track your BMI, body fat, and ideal weight over time. Use the Blood Pressure Calculator to understand your readings.
All Health & Fitness Calculators
Formulas sourced from WHO, CDC, and published clinical research.
BMI Calculator
Most PopularCalculate your Body Mass Index using WHO classification standards. Includes healthy weight range and context.
BMR Calculator
EssentialCalculate your Basal Metabolic Rate using the Mifflin-St Jeor equation — the most accurate formula for most adults.
Calorie Calculator
Find your Total Daily Energy Expenditure (TDEE) based on activity level. The foundation of any nutrition plan.
Macro Calculator
Calculate your ideal protein, carbohydrate, and fat targets based on your goals (weight loss, maintenance, muscle gain).
Body Fat Calculator
Estimate body fat percentage using the U.S. Navy circumference method. No equipment required.
Ideal Weight Calculator
Calculate ideal body weight using the Devine formula alongside BMI-based healthy weight range.
Calorie Burn Calculator
Estimate calories burned for hundreds of activities using MET-based calculations.
Water Intake Calculator
Calculate your daily hydration needs based on weight, activity level, and climate.
Protein Intake Calculator
Find your optimal daily protein intake based on weight, activity, and fitness goals.
Sleep Calculator
Calculate optimal bedtimes and wake times based on sleep cycles to wake up feeling refreshed.
Target Heart Rate Calculator
Find your target heart rate zones for fat burning, cardio, and peak performance.
Running Pace Calculator
Calculate running pace, finish time, or distance for any race or training run.
Lean Body Mass Calculator
Calculate your fat-free mass to track muscle-building progress accurately.
Blood Pressure Calculator
Understand your blood pressure reading using AHA classification standards.
Health & Fitness Guides
Health & Fitness Apps
Once you know your numbers, these tools can help you track them consistently.