Thanks Stacks but...

That doesnt seem right. Arent you supposed to add something before multiplying # of outs by 2?

Using your method, if we have 9 outs it gives us an 18% chance of hitting one on the turn. However, 9/47(100/1)=19.14%

Its a small difference sure, but if were allin on the flop that diff is doubled. In some cases the difference is nearly 3%. Believe me Im not picking holes. I just thought there was a number to add before multiplying by 2.