why dont you cut strips of newspaper and make a paper border and then measure.

Did you all read what the OP wrote? She's (he?) is asking about mitered seams in the length of the border, not mitered corner seams.

I guess I just don't think of the straight border (put together with miters) as creating any waste.

So you're suggesting I measure like this for, say, a 60" quilt side measurement

I should cut one one WOW strip (40" ) of the border width (5" ), and then calculate the additional needed (20" ) plus an additional width amount? And then only cut the second strip 25" x 5"? (ignoring seam allowances on purpose)

While I usually cut lengthwise borders as a matter of habit, if I were going to do it WOW, I would just cut a whole other strip anyway. I never think of that as waste.

I never thought about making up a formula for calculating the number of strips to cut for a border. I approximate the number of strips and sew them together. If I need another strip, I cut it and add it to the border piece going on the last side. So now I know I need to add the width of the border plus 1/2" for seam for every seam in the border.

AudryB - Thanks for the equation. It answers my question about the corners. I must have misinterpreted the question, as I thought it was about the extra corner length required.

Linda

Thank you for the info everyone! :)