The window width rounded up to nearest whole number. For external mounting, include molding in width. 1-inch (25 mm) is automatically added to each panel for hems.

The finished height rounded up to nearest whole number. Not including top and bottom hems.

Add together the finished width of top and bottom sleeves. If double hems are needed, double the width. Round the result up to nearest whole number

Total number of curtains (panel pairs) with these dimensions.

Width of fabric rounded down to the nearest whole number (often 46, 54, or 60 inches -- 1168, 1372, and 1524 mm)

Amount of gather in the finished curtain. 1.5 times fullness is good for thicker fabrics, 2 times fullness is average for draperies, and sheers generally have 3 times fullness.

The vertical repeat of a patterned fabric. Enter "0" if the fabric does not have a pattern. Decimals are permitted.