Watt and Wall

Window decoration calculator

Curtain Measurement Calculator

Plan an outside-mount rod, total curtain fullness, whole ready-made panel count, and finished drop using metric or imperial measurements.

Your measurements

Plan ready-made curtain panels

Use the outside window width, available wall space, packaged panel width, and your intended finished drop. The panel result always rounds up to a whole item.

Changing units converts the window, rod, panel, and drop measurements as one set.

The cited IKEA guide illustrates 2× and 2.5×. Match the choice to your panel header and product instructions.

Window, rod, and panels

Measure outside trim for an outside mount.

Starting point: 23 cm / 9 in.

Use the packaged panel width.

Measure from rod or ring to the desired hem.

Live estimate

Curtain and rod estimate

Suggested rod width 226 cm (2.26 m), 4 panels, finished drop 220 cm (2.2 m).

Whole panels to buy

4

Rounded up at 2× fullness

Suggested rod width
226 cm (2.26 m)
Combined fabric width
452 cm (4.52 m)
Finished drop
220 cm (2.2 m)

Check the panel header, rings, hems, pattern repeat, shrinkage, and manufacturer instructions before ordering or cutting fabric.

Ready-made panel estimate

Curtain measurement formula

An outside-mount rod extends beyond both sides of the window. Fullness multiplies that complete rod width, and the panel count rounds up so the combined packaged width meets the target.

Rod width = window width + (side extension × 2)

Total fabric width = rod width × fullness

Panels = round total width ÷ one panel width up

Measure the installed position

Use the full rod length for panel width and measure the finished drop from the actual rod or ring position. Header type, rings, hems, pattern matching, fabric shrinkage, radiators, and floor clearance can change the final order.

Read the curtain measuring guide.

Turn panel count into a purchase quantity

For a chosen 210 cm window with 25 cm of rod extension on each side, the rod is 260 cm wide. At 2.5× fullness, the target fabric width is 650 cm. If one panel is 130 cm wide, five individual panels meet that target exactly. These are example inputs, not a standard window size.

If the selected product is sold as a pair, five panels means buying three two-panel packages, leaving one extra panel. Check whether an odd number of hanging panels suits the opening, then compare the actual package dimensions and price. The calculator reports panels, not packages.