Those are not the best calculators for a number of reasons, and they are all too basic to give anything accurate for actual rides. Height is not a large factor, and I think it's a roundabout effort to get a body mass index figure. Body mass index can also be deceptive because higher mass with lower body fat will burn far more calories than with higher body fat percentage. The ride you are calculating is also problematic because you are putting in one set of figures for a ride that is likely composed of distinctly different types of terrain. You can get a reasonable estimate by dividing the ride into climbing, descending and flat sections and then adding the results for total calories. The fact that you are 6'5" and 215 to me implies that you are fairly lean, and maybe 600-700 per hour might not be that far off. Try Bike Calculator and see what you come up with.