Then 5" ought to be enough, if you only knit an inch or 2, the stitches will measure wider than they should.
You're still not understanding the part about measuring how many stitches per inch you have. I think it's a little of 5 per inch - but measure carefully across 4" of your piece, then divide by 4. That's how many sts in an inch of your pattern, then multiply that by 22 and 23 to see whether 116 or 128 will get you that measurement.
sue- knitting heretic