Measure your window accurately for recess or exact-fit blinds, checking width, height, depth and squareness before ordering.
MW-01Get your tools togetherUse a metal tape measure, not a fabric one, as fabric can stretch and throw your numbers off. Grab a pencil and notepad to record every measurement as you go. If the window is high up, use a stable step stool rather than a chair.
1 each · Metal tape measure (3m) MW-02Decide recess or exact fitA recess (inside) mount sits inside the window reveal and needs at least 50-75mm of clear depth, more for a Venetian blind, to allow the blind to sit flush without catching on handles. An exact (outside) mount fixes to the wall or frame around the opening and covers more of the window, giving better light block-out. Check the recess depth and any handles or locks before you choose.
MW-03Measure the recess depthFor a recess mount, measure how deep the recess is at a few points across the width. Use the shallowest reading, since that is what limits which blind will fit. If a window handle or lock sticks out into the recess, measure to that point instead of the wall, as it will restrict clearance.
MW-04Measure the recess widthMeasure the width inside the recess at the top, middle and bottom. Write down all three numbers. When you order, use the smallest of the three so the blind fits without you having to force it in.
MW-05Measure the recess heightMeasure the height inside the recess at the left side, middle and right side. Write down all three. This time use the largest number, so the blind covers the full recess with no gap at top or bottom.
MW-06Measure for an exact (outside) mountIf you are fitting outside the recess, measure the width and height of the window frame or opening itself. Add an overlap allowance, typically 100mm either side and 70-100mm above the top, to block more light and cover any gaps. This overlap varies between blind types and suppliers, so check the maker's guidance before you finalise it.
MW-07Check the window is squareMeasure both diagonals of the recess or opening, corner to corner. If the two diagonal measurements differ by more than a few millimetres, the window is out of square. Note this down, as some suppliers can adjust the blind shape slightly to compensate.
MW-08Note any obstructionsLook for window handles, locks, sills, radiators or trickle vents that sit inside or near the recess. Measure how much they stick out, as this affects both the mount type and how the blind will operate once fitted.
MW-09Double-check and finalise your figuresRe-measure each width, height and depth one more time before writing down your final numbers. Always work in millimetres, not centimetres, to avoid decimal-point mistakes when ordering. For a recess mount, shave 2-3mm off each side of your final width for clearance so the blind isn't a tight squeeze.
MW-10Tidy up and keep your measurements safePut your tools away and keep the notepad somewhere you won't lose it, as you'll need these exact figures when you place your order. Take a photo of your notes as a backup.
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