You might find this other bikeforums.net thread of interest: http://www.bikeforums.net/showthread...Day-of-Touring

It contained this:

A good, somewhat general purpose, way to calculate calories burned is to use a coefficient. I use a coefficient of 0.28 - calories/mile/pound.

DISTANCE * WEIGHT * COEFFICIENT = CALORIES BURNED

So if you do 70 miles and weigh 165 lbs and carry 45 lbs:

70 * (165 + 45) * .28 = 4116 calories

Ray