The distance needed to burn a set number of calories by walking depends on the walker's weight, according to Fitness for Weight Loss. For instance, a 200-pound individual burns 120 calories per mile. Therefore, burning 500 calories at this rate requires walking at least five miles.
Fitness for Weight Loss also includes other weight categories, such as for those who weigh 400 pounds. On average, someone in this weight category burns 240 calories per mile, so walking at least three miles is necessary to burn 500 calories.
The manner of walking also plays a role, according to Healthy Living from AZ Central. Wearing a comfortable pair of walking shoes allows for a more efficient run and faster walking means more calories burned. The site uses the example of a 180-pound individual who must walk at least three miles per hour for one hour and 50 minutes to effectively burn 500 calories. A 220-pound person must walk the same speed for 90 minutes to burn the same number of calories.
Fitness Blender also recommends walking at a brisk pace of four miles per hour for 90 minutes to lose 500 calories. However, About.com notes that walking speed is not as important as weight and distance; the site also provides a calculator that determines burned calories based on weight, distance and miles walked.