How many calories you torch on a walk depends on how much you weigh and how fast you walk. There's some sweet revenge in that: The heavier you are, the more calories you'll burn per hour. And, of course, the faster you walk, the faster you burn calories.
Want to nix a pound just by walking? Burn 3,500 calories and you're there. So if you weigh 150 pounds and walk at a four mph pace for an hour a day, a pound could be gone in just over 10 days -- without dieting!