
Never really thought about it but the schedule gives 24 inches wide as examples for Airedales and Boxers and Bassetts, with 20 for Corgis and 28 for Standard Poodles, and yes 24 inches wide sounds about right. I think they are about 30 inches long.
Edited to say: I don't often use soft crates but just remembered that those I have are 30 inches long and they fit on the bench without any overhang, almost exactly.