TDEE.io is a fast, accurate, free TDEE calculator. Input age, sex, height, weight, and activity level to instantly calculate your Total Daily Energy Expenditure (TDEE) and maintenance calories. Get reliable targets for fat loss, muscle gain, or weight maintenance using the Mifflin-St Jeor equation. It also provides calorie deficit/surplus recommendations and macro guidance, offering a practical starting point to achieve your fitness goals with confidence.