The number of calories you can burn through walking depends on age, gender, body size, and activity level. For example, a moderately active person can burn 2,000 calories by walking 2 to 3 miles a day and doing daily exercises. However, elite athletes can burn it at a faster rate. At the same time, a person weighing 70kg might have to walk for 6-9 hours to meet the calorie-burning goal.