You burn calories all times of day, no matter you do exercise or sit at home. When you saying, breathing, heart beating, they all need calories.
For example, when you are man, 25 years old, 170cms and 65kg, everyday moderately active, you need 2503 calories burned per day.
Man: dci = 66 + 6.23 × w + 12.7 × h - 6.8 × age
Woman: dci = 655 + 4.35 × w + 4.7 × h - 4.7 × age
Where, w is Body weight, in pounds (lbs) or kilograms, h is Body height, in inches or cm, dci is Basal Metabolic Rate, in calories.