Q: dear mike, how many calories are burnt during complet rest in 24 hours. i am 63 years /180 ponds/66inches

A: What you're referring to is called Basal Metabolic Rate (BMR) which is the amount of energy (calories) your body needs to use to just keep all your organs functioning normally. At your age and physique the number given will typically around 1500-1600 calories per day.

The thing to keep in mind is that it's wrong to simplify everything down to calories burnt (BMR calories + activity calories) minus calories eaten. You, regardless of your age or physical condition, have a great degree of freedom in shaping your own metabolism. You can structure your diet, the foods you eat, the exercises you do to boost your metabolism and help you lose fat and weight (if that's your goal) and/or build muscle. It is not at all uncommon for two people of the same age/height/weight to have completely different metabolism. One of them might gain weight eating 2500 calories/day while another would be losing weight doing the same.

So it's not by any means a simple equation where you can just plug in your calories burned minus calories eaten and figure out how much fat you'll lose. What I try to do on this whole site is help you find ways to achieve your own fitness goals and boost your metabolism, no matter your age or physique. For some very simple tips look here.