There's a web site called www.healthstatus.com if you go to that site go to calories burned and you'll find a calories burned estimator, type in your weight, and scroll down to bicycleing, and type in the minutes you spend on your bike in the box that describes in mph how fast you go, then scroll down to the bottom, hit calculate, and it will tell you approx how many calories you burned. I wounder how acurate that is?? For me, at 248lbs, and going 15 mph for 51 mins, my calorie burn is 1099 calories, that seems high to me, but if it's even close, then this bicycleing this is the best kept secret in the world for weight loss.
Paul