Since 3,500 calories equals 1 pound of fat, a 180-pound person is able lose 1 pound by walking 35 miles, according to About.com. Every mile walked burns 100 calories for a person who weighs 180 pounds, and 65 calories per mile for a 120-pound person.
Walking a mile in 13 minutes or less burns weight faster than taking longer to walk 1 mile. To lose the recommended 1 pound per week, a person must burn 500 more calories than is taken in. By increasing walking miles and reducing caloric intake, it is easier to achieve weight loss, according to About.com.