wrench science.com fit calculator
 

anyone have experience with this?

it seems pretty accurate. Though it gave me a shorter reach then What i expected

It's all right, but treat it as a guideline. People here will recommend getting fit in a shop, and while more expensive, it's probably a better bet.

I kind of figured out my bike fit through experimenting on different bikes. My first bike was a 52 cm top tube with a 100mm stem - it was too small. Then I went to a 55 cm top tube with a 110 - too big. Swapped it out for a 90mm stem - still a little too big. My next bike's most likely going to be a 53 cm top tube with a 100 mm stem. Should put me about where I need to be.

any online fit is going to only be a starting point. the WS calculator is as good as any.