Try this one BB
http://members.tripod.com/~gleigh/readtst.htm
It's the Shonell It seems pretty accurate but tests for fluency not comprehension. For my kids and the very bright kids I know, comprehension lags fluency and catches up later.
One way you can gauge comprehension is to ask questions at the end of a book. Or have your child write down every word they don't understand or know. DD8 and I have been having fun with this. But she doesn't like to write them down! She likes to belt them out at me and has me write them down!
But, it's become a game and she has fun. Then we look up definitions and she re-reads the sentence.
