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.
