How to Measure for Curtains: Width, Drop and What a Workroom Needs

Every measurement is taken from the track or pole, so it has to be settled first. A pole is a visible bar on brackets, carrying rings or eyelets. A track is a slimmer profile, wall-fixed on brackets or screwed to the ceiling, with gliders the curtain hooks onto. Eyelet curtains only work on a pole; ripple-fold or wave curtains need their own track; pinch and pencil pleats can go on either. Our guide to types of curtain rods compares the options and the metals that survive salt air.

Next, decide the height. A pole or track just above the window frame is the conventional position, but on a tall window it cuts the wall in two and lets light spill over the top. Fixing higher, close to the ceiling, makes the window read taller and helps a bedroom stay dark. Where the window runs right up to the ceiling, or a beam sits above it, a ceiling curtain track is often the only clean answer.

Finally, decide whether the curtain hangs inside the window recess or outside it, on the wall around the opening. That choice changes which surfaces you measure, so it gets its own section below. If you are still undecided between options, measure for both. It takes two extra minutes per window and saves a second visit with the ladder.

Curtains do not vanish when they are opened. They fold into a stack, and the stack has to go somewhere. If the track stops at the window frame, the open curtain sits over the glass and takes a share of the light and view with it. So the track runs past the window on each side, by roughly the width of the stack. The heavier and fuller the curtain, the bigger the stack and the further the track runs.

Our curtain rod length planner works this out from the window width, the fabric and the heading, using rules of thumb curtain makers use. The table shows what it gives for a centre-opening pair. Note how much the answer moves: a lined pinch-pleat pair on a 180 cm window wants a 330 cm track, about 73 cm past the glass each side, while a sheer on a wave heading needs far less. For a single curtain drawing to one side, the whole stack sits on that side.

Measure the window width across the outside of the frame or architrave, then measure the clear wall either side of it, up to a corner, a pilaster, a wardrobe or a switch. If the planner asks for more wall than you have, the usual answers are a lighter fabric, a wave heading, which stacks tighter, or a single curtain drawing to the open side. Record the wall space either way: a workroom needs it to set the track, and a pair that meets in the middle also needs a little overlap at the centre so no line of light shows.

The drop is the finished length of the curtain, from the top of the heading to the hem. On the job you measure it from the track or pole down to where you want the hem to sit, and tell the workroom which point you measured from: the top of a track, the underside of a ceiling, or the top of a pole. The workroom then sets the heading so that it covers a track or sits correctly against a pole. If the hardware is not up yet, mark its intended height on the wall in pencil and measure from the mark.

Where the hem stops is a design decision with practical consequences. A sill-length curtain stops just above the sill. A below-sill curtain runs past it and covers the trim beneath. A floor-length curtain finishes just clear of the floor, which is what we recommend for most Goan rooms, because tiled floors are mopped daily and a hem that touches the floor wicks up water and grit. Longer styles that break or pool on the floor have their place, mostly in formal, air-conditioned rooms. Our curtain length guide compares all five.

For a floor-length curtain, measure the drop at the left, the centre and the right of the opening. Floors are rarely level and ceilings are rarely flat, and a few millimetres of difference is enough to make one end of a hem drag. Write down all three readings. A workroom will usually make to the shortest so that no part of the hem touches, but it needs all three to judge whether the difference is small enough to ignore.

Many older Goan houses have deep window reveals, with timber shutters that fold back into the opening. A curtain hung inside that recess, on a recess track or a pole fixed between the side walls, keeps the wall around the window clear and suits a room where the frame is part of the architecture. The catch is space. Inside the recess there is nowhere for the stack to go except across the glass, and the curtain has to clear any shutter, handle, latch or sliding insect net that also lives there.

For an inside-recess curtain, measure the width of the recess at the top, the middle and the bottom, because old openings are seldom parallel, and give all three. Measure the depth of the reveal from the face of the wall to the glass or shutter, and the height from the head of the recess to the sill. Note anything that projects: handles, stays, bolts, a net frame. The workroom will make the curtain to fit the narrowest point.

For an outside fixing, measure the window, the wall either side, and the height from the top of the frame to the ceiling or cornice. Check what you are fixing into above the opening. In a modern concrete-framed house the lintel or beam above the window is far stronger than the block infill beside it; in laterite and lime plaster, ordinary plugs can crumble out under a heavy curtain and resin anchors are the safer choice. Our guide to laterite and old walls explains why that matters before a single hole is drilled.

Do not assume that two windows in the same room are the same size. The 1950 manual quoted above warned that even neighbouring windows can differ in height by as much as two inches, about 5 cm, in older buildings and new ones alike. In a Goan house that has been extended, re-roofed or re-floored over a century, the differences can be larger. Measure every window, label each one on a sketch of the room, and never copy one set of numbers to the next.

Out-of-square openings need more readings, not fewer. Measure widths at top, middle and bottom; drops at left, centre and right; and the diagonals of the opening if you suspect it has racked. On an arched head, measure the width at the springing line, where the curve begins, and the height to the top of the arch, and photograph it straight on. Arches and fanlights usually push the track above the arch or onto the ceiling, so the arch stays visible when the curtains are open.

Finished surfaces matter too. If the floor is still to be tiled, or a false ceiling is going in, measure after that work is done, or confirm the finished levels with whoever is doing it. A drop measured to bare screed will be wrong by the thickness of the tile and its bed. In a new-build villa, our new-build handover guide covers what to fix in the order it needs fixing.

A made-to-measure quote is only as good as the information behind it. Two quotes based on different fullness, different track lengths or different drops are not describing the same curtain, so it helps to give every workroom the same set of facts. For each window, send the list below, a photograph taken square-on with the tape visible, and a second photograph of the wall either side.

Even with all of that, a good workroom will measure on site before anything is cut. That is not doubt about your tape; it is the only way to see the fixing surface, the floor level and the obstacles together. Treat your own numbers as the basis for a reliable estimate and for comparing options, and the site measure as the one that goes to the cutting table. When you are ready, our team can measure on site and quote fabric, lining, heading and track together.