How to measure a window for curtains

Measurement isn't "a quick thing so we know how much fabric to order". The precision of this step decides whether the curtain hangs straight and whether the material is enough.

What to prepare

• A rigid tape measure (5 m) - soft tailor's tape stretches; we don't use it.
• A spirit level or phone level - window frames in older buildings are rarely level.
• A notebook - memory stops working at the second window.

Step 1: Decide where the rail goes

The top of the curtain should sit 15-25 cm above the window frame. In low-ceilinged rooms: directly under the ceiling.

Step 2: Measure the rail width

The rail must be 15-30 cm wider than the window on each side. Otherwise the curtain shades part of the glass when drawn open.

Step 3: Measure the length

From the planned rail line down to the floor (or 1-2 cm pooling on the floor for an elegant look), or 1 cm above the floor for a sporty, easier-to-clean finish.

Step 4: Measure at three points

Measure the height at three points (left corner, centre, right corner) and take the smallest value. In old apartments, 2-3 cm differences are normal.

Step 5: Check for obstructions

• Radiator below the window - the curtain shouldn't hang on it (faster soiling, worse heat exchange).
• Protruding sill - make sure the curtain slides freely past it.

DIY or a pro?

For a standard, rectangular window - you'll measure it yourself. For an arch, an odd corner, a curve, or a run wider than 5 m, we'll come and measure it (included in the project).