I have made several king-sized quilts this way ... I do it in sections so I do not have to fuss with one huge strip at the beginning and can press ... determine how wide you want the quilt to be, add a few inches just because you might change your mind or want to square it off and use this measurement as your longest strip ... you could also do the length depending how you want the strips to face on your bed ... usually sew it in 4 "panels" ... sew them together at the end which allows for adjustment if you want it to tuck under the pillows.