How to measure for curtains

Measure the width and add the rod overhang

1. 1
   Measure the trimMeasure from the outside edge of the trim on one side to the outside edge on the other. Measure the trim rather than the glass, because the curtains hang outside the frame.
2. 2
   Add the overhangAdd 8 inches on each side so the open panels cover the wall rather than the glass. A 36-inch window takes a 52-inch rod.
3. 3
   Note the rod widthThe rod width, not the window width, is the number you use for fullness and panel count.

Guides differ on the overhang. The Shade Store says 6 to 12 inches on each side, Nicetown says 8 to 12, and Kwik-Hang says 3 to 6, wider for heavy drapes. The curtain size tool uses 8 inches by default and lets you change it.

Panel width and fullness

Fullness is the flat width of all the fabric divided by the rod width. At 2x, the standard, the panels together measure twice the rod. Use 1.5x for a lighter look and 2.5x to 3x for sheers (The Shade Store, Kwik-Hang). Pinch pleat panels have the fullness sewn in, so you buy them to the rod width.

Many listings are a pack of 2 panels, and some are a single panel. Check the pack size before you count.

How high to hang the rod

Measure from the top of the window trim straight up to the ceiling. Designers hang the rod high so the window looks taller: the curtain tool places it 2 to 6 inches below the ceiling, and never lower than halfway between the window and the ceiling.

Sources put it differently. Nicetown suggests 4 to 6 inches below the ceiling. Painting by the Penny suggests 2 to 3 inches below the ceiling, or 6 to 8 inches above the trim under an 8 ft ceiling. The Shade Store suggests about two thirds of the way from the window to the ceiling, and Kwik-Hang suggests 4 to 8 inches above the frame.

With crown molding, measure to the bottom edge of the molding and treat that as the ceiling. Nicetown suggests leaving 2 to 3 inches below it.

Measure the length for your style

Measure from the rod down to where the hem should end. Nicetown measures from the top of the rod for rod pocket and back tab panels and from the ring for pinch pleats, and suggests measuring at the left, middle and right of the window and using the shortest.

Then round to a stock length. Standard curtain lengths lists which length suits which ceiling. When you fall between two sizes, Kwik-Hang and Nicetown both say to buy the longer one and hem it.

Inside mount and outside mount

An outside mount puts the rod on the wall above and beyond the trim. It makes the window look larger, and it is what the measurements above and the curtain tool assume.

An inside mount puts the rod inside the window recess. Measure the width and height from the inside of the trim (The Shade Store). Nicetown says the recess needs to be at least 3 inches deep and that you should order the rod 1/4 to 1/2 inch narrower than the recess.

• Outside mount: trim width, gap from the trim to the ceiling, ceiling height.
• Inside mount: recess width at the top, middle and bottom, recess height, recess depth.