🪟Curtain Size Calculator

About this tool

Enter the window or recess width, how far the track extends each side, and the height from the track or pole down to the sill. Choose the heading (pencil pleat, eyelet, pinch pleat, wave, tab top, rod pocket or sheer), single or pair, and the length you want. You'll get the track length, each curtain's flat width, the drop, and the nearest UK/EU and US ready-made sizes.

How to measure for curtains

Start with the track or pole. It should be wider than the window, typically 15–20 cm (6–8") past the frame on each side, so open curtains stack back clear of the glass and let in the most light. Mounting it 10–15 cm (4–6") above the frame makes the window look taller. Curtains are cut wider than the track so they hang in soft folds. This fullness depends on the heading: about 2 to 2.5 times the track for pencil and pinch pleats, 1.5 to 2 times for eyelets (grommets), around 2 times for wave headings and up to 2.5 times for voiles. A 150 cm window with 20 cm either side takes a 190 cm track, and pencil pleats at 2.25 times need about 428 cm of curtain, so a pair at roughly 214 cm wide each. For the drop, measure from the top of a track, or from the eyelet line for a pole, down to where the curtain should end: just above the sill (about 1 cm clearance), 15 cm below it to cover a radiator gap, 1 cm off the floor so it doesn't drag, or 5–15 cm extra to puddle on the floor. Honest limits: ready-made curtains are quoted per curtain in the UK and Europe but per panel in the US, sizes vary by brand, and lined or blackout curtains hang fuller and stack back more. Measure each window, since they're rarely identical. The fabric yardage calculator and the wallpaper calculator are related.

Frequently asked questions