Pattern help please

I’m working on another baby cardigan and in the directions for the back I am a little unsure as to what exactly they mean. Could someone hopefully clarify this for me please?

Here are the directions:

Continue in St st (k on RS, p on WS) until piece measures approximately 8 1/2" from beg, ending with a WS row-66 total rows including the Garter st border.

My question is this, am I supposed to make sure I hit 8 1/2" or 66 rows?

Thank you!

I’d go with the 8 1/2 inches in case your row gauge is different than theirs. Unless you want it longer, of course. I think they give you the number of rows so you can make the front the same, maybe?

Okay, sounds good to me. I didn’t think of them putting the rows so the front would be the same. Thanks Ingrid!