I did a hair over a century on Sunday. When I got home, my wife asked how many calories I thought I had burned. I'm doing this more for fun (although I could stand to lose 5-10 pounds) so I hadn't thought about it until she asked.
I'm 175, my ride was 100.6 miles, 6 hours and 23 minutes in the saddle, 8 hour total trip time, 16 mph average (had some rough roads around 65-80 mile mark and slowed me down). Generally though, my actual average was anywhere in between 18-20 mph, I generally spin more than mash. Also, this is mostly flatland, with the occasional viaduct.
I did a couple calorie calculators online and I came up with some wildly varying results (all of which seem high to me). Anywhere from 3000-8000 calories burned. I was guessing closer to about 2000 calories.
All I had for the nutrition was a bowl of cereal, strawberries before. A single brownie cliff bar throughout the ride, two mocha cliff gels, and a 24 oz gatorade (and of course a giant plate of french fries, because if you don't stop for fries or ice cream where is the fun?).
I was hungry when I got home, but not exceedingly. My last century, all I had were gels, and an ice cream sandwich (and I was starving when I got home).
Does anyone have a reliable estimator?