Body Fat Calorie Burn Calculator

Are you curious to find out how long or how far you need to walk to burn off the calories in that doughnut you shouldn’t have eaten? Then, you may find this online calculator useful.

Enter your sex, age, height and weight and click Calculate. An estimate of your Resting Energy Expenditure will appear in the top heading. Next, pick an activity from the dropdown menu. The app will calculate the energy burn for the default values shown in the Speed and Duration sliders for the selected activity. You can adjust these two sliders and observe changes to the Energy burn from activity value shown in the header in red. By playing around with the speed and duration values, you should be able to get an idea of how fast and how long you need to carry out an activity to burn the expected energy. The Duration slider will also show distance travelled.

You can also use this calculator as a planning tool for weight loss from a regular physical activity. Enter the average speed and duration of an activity you perform, or plan to perform, on a regular basis. Use the Frequency slider to enter how often you do it. Use the Burn Goal slider to enter your weight loss goal. The approximate time it would take to reach that weight goal will appear in the Time to reach your burn goal line in the header. You can play around with all 4 sliders to do what-if scenarios for a desired weight loss. The calculator operates continuously so you can see the results instantly as you adjust the sliders.

About the Calculations:

This calculator relies on your Resting Energy Expenditure as a baseline in calculating energy burn for the various activities. Resting Energy Expenditure (REE) is often used interchangeably with Resting Metabolic Rate (RMR). It is the energy burned by your body to keep it functioning while you do nothing but rest for a 24 hour period. This energy is usually expressed in Calories or kilocalories and it is used to perform essential body functions such as breathing, maintaining body temperature, blood circulation, cell growth and brain functions.

Both REE and RMR are measured by means of direct or indirect calorimetry gas analysis. Such measurements can be taken at health clubs and some medical clinics but can be expensive and inconvenient. REE/RMR can also be roughly estimated through predictive mathematical equations based on your height, weight, age and sex. Comparisons of various predictive equations found the Mifflin-St Jeor formula to be the most reliable, predicting REE to within 10% of measured with the narrowest error range. This calculator uses the Mifflin-St Jeor formula together with MET values to arrive at energy burn values.

MET (Metabolic Equivalent of Task):

A MET is the ratio of the energy expenditure rate of a body during a physical activity to the rate when the body is at rest. For example, the physical activity of walking 4.0 mph on a level firm surface is rated at a MET of 5. This means that the activity will burn energy at a rate 5 times that of being at rest. If your REE is say 1527 Calories, the amount of energy you would burn per minute while resting is 1527 / (24 x 60) or 1.06 Calories. So, walking at 4.0 mph would burn 1.06 x 5 or 5.3 Calories per minute.

Tables of MET values for hundreds of activities are available in the Compendium of Physical Activities tables which is updated periodically.