Whichever type of crate you choose, it should be at least large enough that your dog can fully stand up in it AND turn around in it. (pbrc.net)
Which type of soft dog crate you choose depends on how you plan to use a it, how often you're going to use it and what type of dog you have. (topdogtips.com)
Whichever type of crate you choose to use, size is important. (thesprucepets.com)