If O.P has read just a few of the calorie calculation threads on BF, it's obvious there's violent agreement that none of the calculators are worth a flip. There's almost as widespread disagreement as to which calculator is less bad than the others. (Note power meters measure power exerted, so they're much better than HR or distance-and-speed based calculators.)
And on top of that sandy foundation you're trying to build a house of calculations to figure out how many of the calories from the oil in the french fries you ate yesterday were burned on a bike ride compared to the potato starch calories? Look up the random number generator in excel instead!