Find your Basal Metabolic Rate — the calories your body burns just to keep you alive at complete rest.
This uses the Mifflin-St Jeor equation, considered one of the most accurate BMR formulas for the general population.
BMR is just your resting energy use — it doesn't include activity. Multiply BMR by an activity factor (roughly 1.2 to 1.9) to estimate your total daily calorie needs, which is what the two figures below show as rough bounds.
BMR is the energy used at complete rest. Your actual daily calorie needs (TDEE) are higher because they include movement, exercise, and digestion.
The Mifflin-St Jeor equation used here is generally considered more accurate than the older Harris-Benedict equation for most adults.