How to measure:
Inside mount: measure the opening inside the window frame — width at top, middle and bottom (use the smallest), height at left, middle and right (use the smallest).
Outside mount: measure the outside of the window frame itself, adding a little overhang so the shutters cover the frame.
Measure twice. Write both numbers down. Anything unusual (sloping frames, obstructions)? Email or text us before ordering — we're happy to help.