text: A calorie is equal to 4.185 joules.  A FOOD calorie is also known as a kilocalorie, or 1000 calories, is 4185 joules.(1) So, just look up how many calories you burn by walking, running etc. (2, 3) and multiply by 4184.\nThere are lots of websites that you can use to estimate calories burned by exercise.  I listed two of them.