How long does it take to lose a pound doing your favorite activity? This will show you the number of minutes of activity required to burn 3500 calories for over 200 different activities. Armed with this information you can lose 5 pounds, lose 10 pounds, lose 20 pounds or more.
Calculator Source: Exercise and Your Heart — A Guide to Physical Activity. National Heart, Lung, and Blood Institute / American Heart Association, DHHS, PHS, NIH Publication No. 93-1677
You have to burn 3500 more calories than you take in to lose one pound.