One of the most frequent questions I receive is: What is what size crate should I buy for my Mini Goldendoodle, I think the article below is very helpful, I love all the detail Dori puts into the article. 

I found these pictures on line. That are awesome and very help help for some of us visual learners in the world.
Our Mini Goldendoodle females usually weigh very close to 20 pounds when adults and our male Mini Goldendoodles usually weigh between 25 and 30 pounds.   I think, if you have the room in your house I would go with the 35.6" L X 22" W X 24.4" H 36" Large, it my seem huge in the beginning put as you can see in the lower picture there is not a lot of extra room for a water or food bowl. 

We bought a Petco Model 600 (up to 40lbs) 30" x 19" x 21" crate with 2 doors (get the one with two doors so you can use in either direction) before we brought her home based on the breeders recommendation (2 doors in my recommendation).  We had the divider in it as Rua weighed all of 4lbs sopping wet when we brought her home.

This is Rua in her crate 5 months ago.  She was 4-1/2 months old here and weighed about 9-1/2lbs.

Here she is today.  She is 10 months, 1 week and 2 days (give or take a minute or two) and weighs just under 17lbs.  She is under 12" at shoulder.  I don't think she is going to get too much bigger...she hasn't changed much weigh-wise in a few months.  Rua has plenty of room in this crate even though she can't STRETCH out (she lays on the floor in a squashed frog position, usually).