SuddlTools

Home & garden

Curtain size calculator: what size curtains do I need?

Hang curtains high and wide and even a small window looks bigger. Enter a few measurements, choose how you want the fabric to fall, and we will work out the rod, the length and the number of panels.

Outside edge to outside edge of the frame.
Check the label. Ready made panels are often 50 to 54 in.

How to measure for curtains

Designers hang curtains higher and wider than the window itself. It makes ceilings look taller and windows look bigger, and when the curtains are open they stack on the wall instead of blocking the light. The calculator follows the same rules.

  1. Measure the window width from the outside edge of the frame on one side to the other.
  2. Add 8 to 12 inches (20 to 30 cm) on each side for the rod, so the stacked curtains clear the glass.
  3. Place the rod 4 to 6 inches (10 to 15 cm) above the frame, or about halfway between the frame and the ceiling if the space is tight.
  4. Measure from the rod down to the floor and adjust for how you want the fabric to fall.

Curtain lengths: float, kiss, break or puddle

StyleHow it looksAdjust the length
FloatHovers just above the floor, clean and practicalAbout 1/2 in (1 cm) shorter than rod to floor
KissJust touches the floor, the most tailored lookExactly rod to floor
BreakA slight bend where the fabric meets the floorAdd 1 to 2 in (3 to 5 cm)
PuddlePools on the floor, romantic and formalAdd 6 to 8 in (15 to 20 cm)

Standard ready made lengths are 63, 84, 95, 108 and 120 inches in the US, and around 160, 213, 229 and 250 centimeters elsewhere. If your ideal length falls between two, buy the longer panel and hem it, or use clip rings to adjust the drop.

How many curtain panels do I need?

Curtains look best when the fabric is about twice as wide as the rod, so they fall in soft folds even when closed. Multiply the rod width by the fullness you want, then divide by the width of one panel and round up to an even number so you have matching pairs. Sheers need more, up to three times the rod width, because thin fabric looks skimpy when stretched flat.

Blackout for bedrooms. In a bedroom, extend the rod a little further and mount it closer to the ceiling so light can't leak around the edges.

For styling ideas, see our bedroom decor ideas and living room decor ideas, and match your fabric with the color palette generator.

Frequently asked questions

How wide should curtains be for my window?
Aim for a rod 16 to 24 inches wider than the window frame, then buy enough panels that the total fabric width is about twice the rod width.
How high should I hang curtains?
4 to 6 inches above the window frame is standard. Hanging them closer to the ceiling makes the room feel taller, as long as the curtains are long enough to reach the floor.
Should curtains touch the floor?
For most rooms, yes. Curtains that just kiss the floor or float half an inch above it look the most polished. Sill length suits kitchens and windows above radiators or furniture.
What size curtains for a 48 inch window?
A 48 inch window needs a rod about 68 inches wide. At 2x fullness that is roughly 135 inches of fabric, so three panels of 50 to 54 inches, rounded up to four (two pairs) for a balanced look.
Is this curtain calculator free?
Yes. It is free, works in inches or centimeters and needs no sign up.