Free curtain size calculator. Enter window width and drop to find the fabric width with fullness and the finished curtain length.
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Multiply window width by 1.5 for comfortable fullness, so curtains gather rather than hanging flat. Add 20 cm to the drop for hems and heading, which covers top and bottom finishing on a standard curtain.
This calculator uses a simple, honest model: fabric width equals window width times 1.5, and fabric length equals drop plus 20 centimetres for hems and heading. A 120 centimetre window therefore needs 180 centimetres of fabric width, and a 150 centimetre drop needs 170 centimetres of fabric length. The 1.5 fullness gives soft folds when closed, without the heavy gathering of a luxury fullness. For a fuller look, use the fullness section below to work out a wider width by hand.
Curtain rod length is the starting point for most guides. If a rod is already fitted, measure the pole between the finials, excluding the finials, or measure a track end to end, adding any overlap. If no rod is fitted, start from window width and add extension per side, commonly 4 to 6 inches, or 6 to 12 inches where you want the open curtains to clear the glass fully. A wider rod also gives stack back room, so open panels sit on the wall instead of covering the window.
Curtain fullness is the ratio of total fabric width to rod length. A fullness of 1.5 gives gentle folds and suits casual rooms and heavier fabrics. A fullness of 2.0 is the standard balanced look for most rooms. A fullness of 2.5 gives deep, luxurious folds for formal rooms, and 3.0 is a maximum for sheers and deep pleats. Pinch pleat, goblet, and box pleat headers have fullness built in, so their ordered width equals rod length rather than rod length times fullness. This calculator uses 1.5 as its comfortable default.
Curtain drop is measured from the correct starting point for the header type, straight down to the chosen endpoint. For an eyelet curtain measurement, start at the top of the pole, and allow about 3 centimetres for the fabric standing above the eyelets. For a pencil pleat curtain measurement, start at the underside of the ring, or the top of the track. For a tab top, start at the top of the pole. Measure drop at left, middle, and right, and use the shortest measurement, because floors are rarely perfectly level.
Curtain length styles change the endpoint, not the measuring method. Sill length finishes about 1 centimetre above the sill. Apron length drops about 15 centimetres below the sill. Float length hovers about 1 centimetre above the floor and is easy to clean under. Kiss length barely touches the floor for a tailored look. Break length adds about 1 inch past the floor for a soft fold. Puddle length adds 2 to 6 inches on the floor for a formal, romantic look, but it collects dust and suits low traffic rooms only.
A curtain panel calculator rule is simple: divide total fabric width by one panel flat width, and round up. For a two way draw, round up to an even number, so there is a pair for each side. Example: a 200 inch total fabric width divided by 50 inch panels gives exactly 4 panels. If the division gives 3.5, round up to 4 panels. Always use the flat width of a panel, not its gathered width, and check whether panels are sold singly or in pairs before ordering.
Standard curtain sizes in inches are 63, 84, 96, 108, and 120, with 132 and 144 also available from some makers. A 63 inch length suits sill and apron styles, 84 inches suits shorter walls, 96 inches suits floor length on standard 8 foot ceilings, 108 inches suits 9 foot ceilings and high rods, and 120 inches suits 10 foot ceilings and puddle styles. If your drop falls between two standard sizes, buy the longer size and hem it down: a short curtain cannot be stretched longer.
Bay window curtains need each section measured separately, with one rod per section or a bending bay rod. Sliding door curtains need extra stack back, because open panels must clear the door: budget about 30 percent extra rod on the stack side for a sliding door. Corner windows, arched windows, and above sink cafe curtains each need their own section measurements. Common mistakes are measuring the frame instead of the rod position, forgetting fullness, ignoring heading height, measuring before the rug is down, and hanging the rod at the frame instead of 4 to 8 inches above it.
At least 1.5 times the window width for a comfortable gather, and 2 times or more for a fuller look. This calculator uses 1.5 as its default, so a 120 centimetre window needs 180 centimetres of fabric width.
Measure the window width, then add extension per side for brackets and finials, commonly 20 centimetres each side, or 40 centimetres total. That gives the rod length to use for width and fullness.
Measure the recess width for an inside mount, or the track end to end for an outside mount, adding any overlap. For a track outside the recess, add about 10 centimetres each side.
Divide total fabric width by one panel flat width and round up, to an even number for a two way draw. For example, 200 inches divided by 50 inch panels gives 4 panels.
Commonly 4 to 8 inches above the frame, and up to 12 inches with tall ceilings. A higher rod makes the window and the ceiling look taller.
Float length, about 1 centimetre above the floor, is the low maintenance default. Kiss length barely touches the floor for a tailored look, and puddle length pools 2 to 6 inches on the floor for formal rooms only.
Fullness is total fabric width divided by rod length. Choose 1.5 for light and casual folds, 2.0 for a standard balanced look, and 2.5 for deep luxury folds. Pre pleated headers have fullness built in.
For eyelet and grommet curtains, measure from the top of the pole and allow about 3 centimetres above the eyelets. For pencil pleat, measure from the underside of the ring or the top of the track. For tab tops, measure from the top of the pole.
Yes. Hang them, mark 5 centimetres past the desired end, cut, fold 2.5 centimetres twice, and pin, sew, or use no sew tape. Buying longer and hemming down is easier than fixing a curtain that is too short.
Measure each bay section separately. For a sliding door, extend the rod well past the door on the stack side, about 30 percent extra, so open panels do not block the door.
Standard lengths are 63, 84, 96, 108, and 120 inches. Pick the length for your ceiling and style, and if you fall between sizes, buy the longer size and hem it down.