One of the most common questions I get asked is “How many calories can I burn with walking?” And, the best (yet unsatisfying) answer is “It depends.” There are no precise formulas for burning calories with walking. Metabolism is a complex and individual process, so definitive answers about it require exact measurements you can only obtain in a lab. And, if you repeat the tests in a few months, odds are you’ll get different answers because your body is a living, always changing organism.

However, you can use averages that will give you a guideline to balancing your caloric intake and physical activity so that you can maintain your desired weight. These formulas are based on average calorie burning rates, plus your own weight, walking speed and time spent walking.

These formulas start with a walking speed of 2 miles per hour and increase to a walking speed of 5 miles per hour. To determine how many calories you burn walking, find your walking speed and then use the formula below it to determine how many calories you burned.

2.0 or Two miles per hour (thirty minute mile)

1 X your weight X 1 for one hour (use .25 for 15 minutes, .50 for thirty minutes and .75 for 45 minutes.)

2.5 or Two and a half miles per hour (24 minute mile)

1.3 X your weight X 1 for one hour (use .25 for 15 minutes, .50 for thirty minutes and .75 for 45 minutes.)

3.0 or Three miles per hour (20 minutes per mile)

1.5 X your weight X 1 for one hour (use .25 for 15 minutes, .50 for thirty minutes and .75 for 45 minutes.)

3.5 or Three and a half miles per hour (17 minute mile)

1.8 X your weight X 1 for one hour (use .25 for 15 minutes, .50 for thirty minutes and .75 for 45 minutes)

4.0 or Four miles per hour (15 minutes per mile)

2.3 X your weight X 1 for one hour (use .25 for 15 minutes, .50 for thirty minutes and .75 for 45 minutes.)

4.5 or Five and a half miles per hour (13 minute pace)

3.0 X your weight X 1 for one hour (use .25 for 15 minutes, .50 for thirty minutes and .75 for 45 minutes)

5.0 or Five miles per hour (12 minute mile)

3.6 X your weight X 1 for one hour (use .25 for 15 minutes, .50 for thirty minutes and .75 for 45 minutes.) (At this speed, your body is working very hard and you are burning as much or more calories than you would by running.)

To illustrate an example, let’s use the 150 pound woman and have her walk one hour at 3.0 miles per hour.

So, 1.5 X 150 X 1 hour gives us 225 calories burned. If that woman is normally inactive, she needs 1500 calories per day to maintain her current weight. If she walks one hour three times a week, she burns an additional 675 calories per week. So, she will lose a pound in about five weeks. (A pound is 3500 calories.)

With the thermal effect and muscle building and water loss, she will probably lose it in about a month, again, keeping her food intake exactly the same. Plus, after exercising for about 45 minutes in one session, you begin to burn more fat for energy. She will build more muscle tissue, too, which will burn more calories even at rest.

So, adding this three times a week walk will, over time, help her to lose more than a pound a month, which is a very safe and effective rate of weight loss. Of course, reducing caloric intake will help lose weight more quickly, but don’t go lower than 1,200 calories a day or you could actually decrease your metabolism.

Remember, this is all very much a “guesstimate”, based on averages. So many factors affect metabolism that no formula is exact. Things such as menopause, medications, genetic makeup, thyroid issues, hormone issues, and more can increase or decrease your metabolic rate. But, unless you want to pay for and endure a bunch of very expensive metabolic tests, these estimates will give you a good guideline to go by.

To keep up with your distance and time walking, I recommend the Omron HJ-112 Digital Premium Pedometer.

Accurate portion control is also important, and this EatSmart Digital Nutrition Scale - Professional Food and Nutrient Calculator will help you measure and make better food choices.