There is an easy way to figure out how many calories you are eating every day to maintain your current weight. Multiply your current weight by 12, which will equal the number of calories needed daily to maintain your current weight. For example: if you weigh 150 pounds, multiply that by 12, which will equal 1,800 calories. 1,800 calories then is the number of calories you need every day to main-tain your 150 pounds. If you weigh 125 pounds, multiply 125 X 12 = 1,500 calories, which means that a 125-pound person only needs 1,500 calories a day to maintain his or her 125-pound weight.