Binding Calculator

How the binding math works

Binding wraps the whole outside edge of your quilt, so you start with the perimeter — twice the width plus twice the length. Then we add about 10 inches: a little for each mitred corner and a little for the diagonal seam that closes the loop.

Why diagonal seams

Joining binding strips on the diagonal spreads the bulk of the seam so it never lands as a hard lump on the edge of the quilt. The calculator's 10″ allowance assumes diagonal joins. See the full join walk-through if you haven't done it before.