Quick facts from 2016 Statistics:

Nearly 40% of home buyers think they need 20% down.

The average down payment for the 2016 year was 11% of the purchase price.

You can buy a home with 3.5% down.

How do you take into account all the variables of waiting to save 20% vs buying now with what you have saved. The current market is trending higher for sale prices around the country, and you could expect to pay more for less home some years down the road. The rent that you are paying won't be going down, or of any benefit toward a down payment.  Here is a great tool from the Mortgage Insurance blog  MGIC Connects, hope you find it helpful!