Staples, of all places, came out with this cool little test to see how many words a minute you read. See how you do!
Source: Staples eReader Department
I think it’s a smidge disengenuous because it tells you to read at your normal speed, then clocks you against speed readers (as well as the national average), but I LOVE the part at the end that estimates how quickly you’d finish various books. It estimated I’d read Harry Potter and the Sorcerer’s Stone in less than 3 hours (at 455 words per minute), and I’m pretty sure I did!
How fast do you read? I know I’m slower on some kinds of stories; other ones speed me up because they’re so much fun!