I consider my cast-off to be the same as my cast on... I sorta/kinda count it like half a row!

It depends on the pattern a lot too, and how important and noticeable a small difference would make. Personally, for this project, I would do an extra row of knit, {57, 58, 59, & 60} *then* cast off...
*waits for Ingrid's expert opinion*
