A roller blind is one of the simplest ways to control light and privacy, but only when it is the right size. Too wide and it will not fit inside the window opening; too narrow and light leaks down both sides. This guide shows you how to measure for a made-to-measure roller blind in about ten minutes, with nothing more than a steel tape measure, a pencil and a sheet of paper.
What you need before you start
- A steel tape measure. Fabric or paper tapes stretch and give wrong readings.
- A pencil and paper to write down every reading, in centimetres.
- A few minutes per window. Measure every window separately, even if they look identical: openings in the same room often differ by a few millimetres.
Step 1: Inside or outside the recess?
This is the most important decision, because it changes what you measure.
Inside the recess
The blind sits within the window opening, fixed to the top of the recess. It looks clean and built-in and leaves the wall around the window free. Choose it when the recess is deep enough for the roller and its brackets, and when nothing sticks out of the window frame into the path of the fabric.
Outside the recess
The blind is fixed to the wall or frame above the window and overlaps the opening on every side. Choose it when the recess is shallow, when a handle or a tilt-and-turn sash would hit the fabric, or when you want the darkest possible room. With a blackout fabric, an outside fit is the best way to reduce the strips of light at the edges.
Step 2: Measuring for an inside-recess roller blind
- Width: measure the width of the opening at the top, in the middle and at the bottom. Write down the smallest of the three.
- Drop (height): measure the height on the left, in the centre and on the right, from the top of the recess to the sill. Write down the smallest reading.
- Depth: check how deep the recess is at the top and look for anything that could block the fabric as it rolls down: handles, hinges, locks, tiles or curtain poles.
Enter the recess size exactly as measured. Do not make any deductions: in the Window-All configurator you choose "inside the recess" and we apply the fitting tolerance for you, so the blind fits the opening and still covers the glass.
Step 3: Measuring for an outside-recess roller blind
- Measure the width and height of the opening as above.
- Add an overlap on every side so the blind covers the whole opening. Around 5 cm left and right and 5–10 cm above the opening is a common choice; add more if you want a darker room.
- Check that there is a flat surface for the brackets at the height you chose, and that the lowered blind will clear radiators, sills and window handles.
For an outside-recess blind you enter the finished size you want, overlap included. We make it to exactly that size.
Roller blind measuring mistakes to avoid
- Measuring only once. Walls and recesses are rarely perfectly square. Three readings for width and three for height prevent surprises.
- Mixing up width and drop. Always write width first, then height (for example 100 × 150 cm).
- Rounding up. Write the exact figure. Half a centimetre too much can stop a blind fitting inside the recess.
- Forgetting the handle. On many European windows the handle sits inside the recess. If the fabric would rub against it, fit the blind outside the recess.
- Deducting twice. If you take off a few millimetres yourself and the configurator applies its tolerance too, the blind ends up too narrow.
Which fabric for which room?
Once your measurements are ready, the next choice is the fabric. Blackout is ideal for bedrooms, semi-blackout softens light while keeping the room bright, and screen fabric cuts glare while keeping the view. Our guide to choosing a blackout, semi-blackout or screen roller blind explains the differences room by room. Prefer slats to fabric? The same measuring method works for our venetian blinds.
Ready to order? See your exact price
Our made-to-measure roller blind starts from €42. Open the configurator, choose inside or outside the recess, enter your measurements and fabric, and see your exact price before you pay.
- Shipping: Italy €7.90, EU countries €12.90, USA €24.90 (import duties paid by the recipient).
- We confirm the production and dispatch date by email within 2 business days.
- Questions about your window? Write to us through the contact form.
Measure once, carefully, and your blind will fit first time. And if insects are the problem in summer, pair your blind with a pleated mosquito net, measured exactly the same way.