How to Measure Your Windows
Five minutes, a metal tape measure, and you're done. Measure to the nearest 1/8 inch — our order form accepts eighths — and remember: you're covered by our Perfect Fit Promise. If a blind doesn't fit because of a measuring mistake, we remake it free within 30 days.
Step 1 — Choose your mount type
Inside mount sits within the window frame for a clean, built-in look. Your frame needs at least 3 inches (7.5 cm) of flat depth for the cassette.
Outside mount fixes to the wall or moulding above the window. Choose it for shallow frames, to make windows look larger, or for maximum light blockage.
Step 2 — Inside mount: measure the opening
- Width: measure the inside of the frame at the top, middle and bottom. Use the narrowest of the three.
- Height: measure left side, centre and right side. Use the longest of the three.
- Order the exact opening size. Do not make any deductions — we take the small clearance allowances ourselves so the blind operates smoothly.
Step 2 — Outside mount: measure the area to cover
- Width: measure the opening, then add 3–4 inches total (1.5–2 in per side) to prevent light gaps.
- Height: measure from where the cassette will sit (at least 2–3 inches above the opening) down to the sill — or lower if you want it to overlap.
- Order that final width and height — for outside mounts we make the fabric to the size you give us.
Step 3 — Double-check and order
- Use a metal tape measure — cloth tapes stretch.
- Write width before height (W × H). Every size on our site is width × height.
- Measure every window, even ones that look identical — they rarely are.
Size limits
Every P.M blind is made to order within these ranges: width 12–90 inches, height 20–118 inches, minimum billable area 1.0 m². Need something outside this range? Contact us — wider windows can often be covered with two blinds on one headrail.
Still not sure?
Order free fabric samples, book a free in-home measure in Greater Montreal, or just measure carefully and lean on the Perfect Fit Promise — measuring mistakes are on us.
