I was just wondering if there is a simple way to figure out what percent grade a hill is? I live in a very hilly area and a few of the hills are really steep. I have started doing hill repeats to build up my stamina because this is an area where I am really lacking. Lots of the training programs I've read online tell you find hills of 2-4% or whatever - I'm always curious to know what % the hills I'm riding are. Is there a simple way to figure it out? (PS I do understand that 10% grade is 1 foot in height increase over a 10 foot distance. Problem is, I have no idea what the vertical change has been over a particular length.)

PS I did find this calculator online....

http://www.csgnetwork.com/inclinedeclinegradecalc.html