Curtain Pleat & Fabric Calculator
Calculate the total fabric width and yardage needed for curtains or drapes based on window size, fullness factor, and heading allowances.
Results
What is it?
Curtain fabric calculation multiplies the window width by a fullness factor (how gathered or pleated the fabric will be) to get the total fabric width needed. The fabric length adds the drop (window measurement) plus heading and hem allowances. Fullness factor of 2.0x is standard — fabric hangs with moderate, attractive drape; 2.5x or 3.0x creates rich, lush pleats.
How to use
Measure your rod width (window width), the drop from rod to desired hem location, and enter heading and hem allowances. Select your desired fullness factor and number of panels. The calculator shows total fabric width, panel dimensions, and total yardage.
Example scenario
60-inch window, 84-inch drop, 4-inch heading, 4-inch hem, 2.0x fullness, 2 panels: Total fabric width = 120 inches, length per panel = 92 inches, width per panel = 60 inches. Yardage at 54-inch fabric = (92 x 2 x 60) / (36 x 54) = approximately 5.69 yards.
Pro tip
For patterned fabric, add extra yardage for pattern repeat matching — typically one full pattern repeat per panel. For sheer curtains, 2.5-3x fullness gives the best effect; for blackout or heavy fabric, 1.5-2x is sufficient due to the weight. Always buy 10-15% extra fabric for cutting errors and future repairs. Pre-wash fabric before cutting to prevent shrinkage — curtains are hard to re-hem.