Free Health & Fitness Calculators

Use our research-backed calculators to optimize your health and fitness. Each tool is based on peer-reviewed scientific formulas and reviewed by health professionals.

All Articles in Free Health & Fitness Calculators

Vitamin D Dosage Calculator - Find Your Optimal Daily Intake

Free vitamin D calculator based on Endocrine Society guidelines. Calculate your optimal vitamin D3 dosage based on current blood levels, weight, and …

TDEE Calculator: Calculate Your Total Daily Energy Expenditure

Free TDEE calculator using the Mifflin-St Jeor equation. Calculate your BMR, TDEE, and macros for weight loss, maintenance, or muscle gain. Backed by …

Dog Calorie Calculator - Daily Caloric Needs by Weight & Activity

Free dog calorie calculator using veterinary RER/MER formulas. Calculate your dog's daily caloric needs based on weight, age, activity level, and body …

Caffeine Half-Life Calculator: When Will Caffeine Leave Your System

Calculate how long caffeine stays in your system. See hour-by-hour caffeine levels and find the best time to stop drinking coffee for better sleep.