How big will my schnauzer / lab mix get?

How big are the parents? That's you best judge of size.

I'd say about this high -

When it comes to mixed breeds there's really no way to determine the size they'll be when fully grown. Mainly that's because most mixed breeds are mixed with more than just two breeds, as the parents are usually mixed as well.

I had a lab/border collie cross. His father was a pure bred border collie, weighed around 40 pounds soaking wet. His mother was a lab cross, also on the small side, around 50 pounds. My lab ended up being a good 10 inches taller than both of them, and weighed in at 80 pounds when he was full grown.

When it comes to mixes, you get what you get, there's no way to even make an educated guess.

We'd love pictures. :)

I love your answer, Judy!

Thank you for the comment and my first smile of the day!