Size can depend on genre. I write YA, and the majority of YA is 5.25 x 8. Some are 5.5 x 8.5.
IMO, sizes should 'match' the books next to them on a bookshelf.
Look at your genre and check your own bokshelf or a local library/book store.
IMO, sizes should 'match' the books next to them on a bookshelf.
Look at your genre and check your own bokshelf or a local library/book store.