Measure the width first, then the height, and always to the nearest 1/8 of an inch. For an inside mount we take your exact opening and make the deduction ourselves — do not subtract anything.
Inside mount (inside the window opening)
- Width: measure the opening at the top, middle and bottom. Write down the narrowest of the three.
- Height: measure from the top of the opening to the sill at the left, middle and right. Use the longest of the three.
- Depth: check you have at least 2″ of flat depth for the cassette to sit inside.
Give us the raw opening size. We make the factory deduction so the shade clears the frame.
Outside mount (on the wall or frame)
- Width: measure the area you want covered and add at least 2″ on each side for light gap control.
- Height: measure from where the headrail will sit down to where you want the shade to end, adding 2–3″ above the opening.
Chain drop
Our shades are raised and lowered with a continuous-loop chain, and you pick the chain drop to suit the window. Note the window height along with your measurements and we will supply a matching drop. If you are between sizes, choose the shorter one.
Common mistakes
- Rounding to the nearest inch. Use 1/8″ increments — windows are rarely square.
- Measuring one spot only. Always take three and follow the rule above.
- Deducting for an inside mount. We do that for you.
- Measuring only one window. Orders start at three blinds, so measure them all in one pass.
Mis-measured anyway? Our remake guarantee covers one blind per customer.