How Wide Should a Curtain Rod Be? The Guide to Rod and Track Length

Open curtains do not disappear; they fold into a stack. The planner sizes that stack from the flat width of fabric on the track, which is the track length times the fullness of the heading. It takes about 12% of that flat width for a sheer, 16% for an unlined curtain and 20% for a lined one, and stacks a wave heading about 15% tighter than the others because its folds nest together. These are rules of thumb used by curtain makers; heavier cloth and interlining stack wider still.

There is a circularity in this that the planner handles for you. A longer track holds more fabric, and more fabric makes a bigger stack, which wants a longer track. The planner works the figure out step by step until track and stack agree, then rounds the track up to the next 5 cm. The fullness it uses is the same as our fabric calculator: 2.25 times for pinch pleat and 2.2 times for wave and eyelet.

The table shows the result for one 200 cm window in all nine combinations the planner offers, as a centre-opening pair. Read across a row and the heading changes the answer by up to about 45 cm; read down a column and the fabric changes it by up to 90 cm. That spread is why the question deserves more than a single number.

Stack-back is the width a curtain occupies when it is drawn fully open, measured along the track. For a pair it is split between the two sides; for a single curtain drawing one way, all of it sits on one side. It is set by three things: how much fabric is on the track, which is fullness; how thick that fabric is, which is lining and weight; and how the heading folds, which is why a wave curtain stacks tighter than a pinch pleat of the same cloth.

In a small room the stack is the difference between a bright window and a dim one. Take a 120 cm bedroom window with lined pinch-pleat curtains. By the planner's own stack rule, a track cut to the window carries 270 cm of flat fabric and stacks about 54 cm of it, 27 cm on each side, all of it over the glass. That is nearly half the window covered by curtain on a sunny morning with the curtains open. Run the track to the planner's 220 cm instead and the same curtains stack about 49 cm each side, entirely on the wall.

Width also changes how the window looks. A track that runs past the frame makes the window read wider, and the open curtains frame it rather than narrow it. A 1950 curtain-making manual gave the same advice for tall, narrow windows: extend the top of the frame and hang draperies from rods that run the full width of the extension, to make the window seem wider.

Because the planner's stack grows in proportion to the track, the extension each side works out as a fairly steady share of the window width for each combination. That gives a rule of thumb that is far more honest than a fixed number, and the table sets it out. For a lined pinch-pleat pair, allow roughly 40% of the window width on each side; for a sheer on a wave heading, roughly 14%.

Lining is the biggest single factor. On the 200 cm window, going from sheer to lined pinch pleat more than doubles the extension each side, from about 37 cm to about 81 cm. The heading is the second: switching that lined curtain from pinch pleat to wave saves about 21 cm a side. Eyelet stacks almost as wide as pinch pleat, because its folds are deep.

These shares are planning figures, not promises. Very heavy fabrics, interlined curtains and thick textures stack wider; light polyester sheers can stack tighter. Use the planner with your own window width, then confirm on site, because the real stack depends on the actual cloth. A short trial of the chosen fabric gathered by hand against a tape measure tells you a lot.

Height changes the room as much as width. A rod fixed just above the frame cuts the wall in two, makes a tall window look shorter and leaves a gap above the curtain for light. Fixing higher, close to the ceiling or cornice, carries the curtain the full height of the wall and makes the window read taller. The 1950 manual suggested a valance board just below ceiling height as a way to increase apparent height, and for a wall of draperies measured the drop from just below the ceiling moulding.

There are practical reasons too. US Department of Energy guidance on fitting draperies advises hanging them close to the window and, for best effect, installing a cornice at the top or placing the drapery against the ceiling, then sealing the sides and overlapping the centre. The UK blinds trade body makes the matching point about light: a blind fixed outside the reveal, rather than inside it, lets less light creep round its edges. A curtain that starts at the ceiling has no gap above it at all, which is why a ceiling curtain track is our usual choice for bedrooms.

A rod needs wall above the frame for its brackets, and the brackets need something solid to fix into. In concrete-framed houses the lintel or beam above the window is far stronger than the block infill; in laterite and lime plaster, ordinary plugs can pull out under a heavy curtain. Our guide to laterite and old walls, linked below, explains the fixings. Remember that height and drop are linked: raising the rod lengthens every curtain, which our curtain length guide and the fabric calculator help you cost.

Many windows do not have the ideal wall on both sides. A window in the corner of a bedroom, a frame beside a wardrobe or a cupboard, or an opening next to a column leaves room on one side only. The usual answer is a single curtain drawing one way, to the side that has space. The planner's single-curtain setting puts the whole stack on that side.

The table shows what that asks for on a 150 cm window. A lined pinch-pleat curtain needs about 122 cm of wall on the open side; the same curtain on a wave heading needs about 89 cm; an unlined wave curtain about 64 cm; a sheer wave curtain about 43 cm. If even the smallest figure is more than you have, the curtain will cover some glass when open, and it is worth deciding where that loss is least noticed.

Other routes help when wall is short. Choose a lighter fabric or a wave heading, which both stack tighter. Hang the curtain as a dress curtain that stays partly closed and put the working layer in the window itself, such as a roller or Roman blind inside the reveal, which needs no wall at all. In older Goan houses with deep reveals and shutters, a blind in the reveal with a narrow curtain outside is often the neatest answer.

A door is less forgiving than a window. A curtain that covers a few centimetres of glass on a window is a nuisance; one that hangs into the doorway is caught by every person, pet and sliding panel that passes, and a sheer drawn into a sliding door's track is torn when the door closes. For doors, the open stack must sit entirely on the wall beside the frame, with the handle, any insect net frame and the walkway clear.

The planner's figures for doors are larger than people expect. A 240 cm sliding door with lined wave curtains in a pair needs a 385 cm track, about 72 cm each side; drawn as a single curtain to one side, the same track carries about 143 cm of stack on that side. A 300 cm opening onto a verandah needs about 480 cm for lined wave curtains in a pair, but only 390 cm for sheer wave curtains, about 43 cm each side. Where a sheer and a lined curtain share a double track, run both on the longer line so neither stack ends up across the door.

On wide doors a wave heading is usually the right choice, because it stacks tighter and runs smoothly every time. Long, heavy runs that are drawn many times a day are also good candidates for a motor. Our ripple fold curtains and curtain tracks pages cover both.