Start with the distance around the quilt
Binding commonly begins as strips joined into one long length. The strip wraps over the quilt’s trimmed edge and is secured on both sides.
For a rectangular quilt measuring 60 × 72 inches, the perimeter is 2 × (60 + 72) = 264 inches. That is the distance around the edge before adding fabric for joining strips, turning corners, and joining the final ends. Use the extra length your binding method calls for.
Strip width affects fabric quantity
The width you cut depends on the binding method and finished width you want. A cut strip width and the visible width of the finished binding are different measurements.
Plan binding separately from the backing. Knowing the quilt’s perimeter alone does not tell you the yardage to buy; you also need the strip width, usable fabric width, and joining allowances.