Where should a curtain finish?

The rail is the starting point

Curtain length is measured from the hanging system, not simply from the top of the window glass. The exact starting point depends on the heading. Rings, eyelets and track hooks position the fabric differently. If the rail is already installed, measure from the point specified for the curtain style you intend to use.

If there is no rail yet, decide its position before ordering finished curtains. A sample photograph with a high ceiling can make a standard panel appear longer than it will be in your room. Mark the proposed height and finish position, then measure the actual distance between them. Do not use a ladder or stand on furniture that is unsuitable for the task.

Check more than one point along the window. Floors and rails are not always perfectly level, and a curtain ordered to skim the floor may drag at one end. Write down the shortest and longest measurement and discuss the appropriate finished length with the seller or maker if the difference matters.

For an existing pair that fits well, measure the old curtain too, but use it as a cross-check rather than the sole reference. Note where its hooks are set and whether the hem has changed through washing. If the replacement uses different rings or a different heading, the same overall cloth length may finish at another height. Keep those two measurements separate in your notes: the room measurement and the old panel measurement.

Decide what happens at the bottom

A curtain that finishes above the floor is easier to move past and clean beneath. One that pools on the floor gives a different appearance but asks for more space and handling. In a room that is mopped regularly, a dragging hem may collect moisture even though the curtain itself has not been washed.

For a window above a desk or built-in seat, floor length may not be possible. Open the window, use the desk chair and check the position of handles. The fabric should not prevent normal access or fall across equipment. Keep curtains clear of heat sources and cooking areas; decorative length is never a reason to put moving cloth near flame.

Balcony doors deserve a separate check. Pull the intended curtain line aside and walk through the opening. Consider where the fabric will gather when the door is open and whether its hem could get trapped under the door. In a windy room, a very long loose panel may move farther than the still display suggests.

Width changes how the length looks

Fullness adds folds, and those folds affect how a curtain hangs. A panel stretched almost flat across a wide window may appear different from the same panel in a generously gathered arrangement. Check the recommended total width for the heading and count how many panels the package contains.

IKEA's curtain planning guidance also separates the window measurement from the space needed for the curtains to open beside it. That side space is useful to check before concentrating only on the hem. A perfectly measured length cannot compensate for a panel that never moves clear of the glass.

For a pair, confirm whether the listed width applies to each panel or both together. Draw a quick rectangle with the rail span, intended drop and number of panels. That small sketch is often easier to communicate to a shop than a description such as long curtains for a large window.

Before shortening a new pair

Read the care label and the manufacturer's shrinkage guidance before hemming. Some washable curtains should be washed as directed before the final alteration; others have coatings or constructions that need a different approach. Do not assume every fabric can be ironed onto hemming tape.

Keep the original excess until the finished curtains have been rehung and checked. Test the closing position as well as the open position. A hem that appears level while the curtain is spread across the window may behave differently when gathered. Once the result works, record the finished measurements for that window rather than relying on the size name on the packet.

If you are sending measurements to someone making the curtains, confirm whether they want the finished drop or a measurement from which they will calculate allowances. Do not add an extra hem allowance silently. Label each window and each measurement, and include a photograph showing the hardware. A few clear notes reduce the chance that both you and the maker add the same allowance, leaving an unexpectedly long curtain.