Estimate the amount of calories that you burn from walking any distance. The grade (i.e. incline or decline of the walking surface) is taken into consideration.
Estimate the amount of calories that you burn based on your average heart rate while exercising.
There are actually four different calculators here that allow you to estimate your VO2max based on your resting heart rate or on performance of a variety of physical exertion tests.
Estimate the amount of calories that you burn from running any distance. The grade (i.e. incline or decline of the running surface) is taken into consideration.