When we sleep, our body cells require very little calories because the total work done is very less. The cells have to only live with bare minimum calories all over the body, only the cells of the heart, lungs, kidneys and digestive system have to work continuously. This needs the lowest number of calories per minute which is about half to less than one calories per minute for an adult.
When we sit down some more cells of the muscles become active and the requirement can go up to one and a half calories per minute. If we start working while sitting like working on the computer when our hands have to do some additional work- so the calorie requirement goes a little up.
When we stand and start doing some cooking, brushing, cleaning, changing our dresses, taking a shower the calorie consumption further goes up to 2-3 calories per minute as more muscles become active now.
Similarly, when we walk, more calories are required by our body. A causal walk needs about 3-4 calories, good speed walk about 5-6 calories, jogging requires about 7-9 calories and running requires about 10-12 calories per minute.
Each of the activities of our body needs some extra calories depending on how many muscles are active during that activity. For most of us, who are sedentary working class (clerks, doctors, business persons, executives, housewives with domestic help) need about 1600 calories per day.
A laborer working for a construction work, who has to carry heavy weights continuously, or a porter in the railway station or a rickshaw puller will need much more calories than a sedentary person. If you are a sportsman who has to practice 5-6 hour per day may require about 3000 calories per day.