Updated October 28, 2026
How to measure for curtains
Curtains look expensive when they are hung high, wide and full. Work out the rod width, the number of panels and the length, then buy once.
Curtain size calculator
How to measure
Width
Measure the window from outside trim to outside trim. The rod should extend 4 to 6 inches past each side, or up to 10 to 12 inches if you want the curtains to clear the glass completely. That makes the rod width the window width plus both extensions.
Fullness
Curtains need more fabric than the rod is wide, or they look flat. Multiply the rod width by 2 for a standard look, 2.5 for a very full one, and at least 1.5 for light, casual styles. Divide the total fabric width by the width of one panel to get the number of panels. Panels usually come in pairs, so round up to an even number.
Height
Mount the rod 4 to 6 inches above the window frame. Mounting nearer the ceiling makes the ceiling feel taller. Measure from the floor to the rod. If your curtains hang from rings or clips, subtract the drop between the rod and the top of the fabric.
Length
| Style | Where the hem sits | Good for |
|---|---|---|
| Float | About ½ inch above the floor | Everyday rooms, easy to clean around |
| Kiss | Barely touching the floor | A tailored look; needs an exact measurement |
| Puddle | 2 to 6 inches of extra fabric on the floor | Formal or romantic rooms, low-traffic windows |
Standard curtain lengths
Ready-made curtains usually come in 63, 84, 96, 108 and 120 inches, and sometimes 132 or 144. Buy the next size up from your measurement. You can hem a long curtain shorter, but you can't make a short one longer.
Common mistakes
- Hanging the rod right at the window frame. It makes the window look smaller and the ceiling lower.
- Buying one panel per side with no fullness. Closed curtains should look gathered, not stretched.
- Measuring before the rug is down. A thick rug can change how much floor clearance you have.
- Forgetting the hardware. Rings, hooks and finials change the final length, so measure from where the fabric actually hangs.
Check sizes before you buy. MUSE lets you save products to a board, see whether they fit your room, and turn the board into a shopping list, with rug sizing and curtain math built in.
Try MUSE Studio