Total Daily Energy Expenditure using Mifflin–St Jeor.
Total Daily Energy Expenditure is the total number of calories your body burns each day, including exercise and daily activity. It is calculated by multiplying your Basal Metabolic Rate (BMR) — the calories burned at rest — by an activity multiplier.
This calculator uses the Mifflin–St Jeor equation, which is the most accurate BMR formula for most adults. To lose weight, eat below your TDEE; to gain muscle, eat slightly above it.