Ordering curtains becomes much easier when you measure the fitting, not just the glass. The rod or track determines the finished width, while the drop depends on where the fitting is installed and where you want the fabric to end.
This guide explains how to measure curtain width and length, calculate fullness, and avoid the mistakes that lead to short panels or insufficient coverage. For more fabric-specific guidance, read El Khawaga’s Curtain Fabric Buying Guide and How Much Fabric Do I Need for Curtains or Roman Blinds?.
How to Measure Curtains 2026
Measure the total curtain track or rod width, then multiply it by the fullness factor required by your curtain heading and fabric. For the length, measure from the top of the track or rod to the exact finishing point: sill, below sill, or floor. Always record width and length in the same unit.
What you need before measuring
Use a metal tape measure, pencil, paper, and a sturdy step ladder if the window is high. Measure in centimetres or millimetres and write every result clearly. If the window has already been fitted with a rod or track, measure that fitting. If not, decide where it will be installed before calculating the fabric.
For a professional project, note whether the curtains will be eyelet, pencil pleat, wave, or another heading. The heading changes the amount of fabric and the way the curtain hangs.
Step 1: Measure the curtain width
If a track is already installed, measure the full track from end to end. Do not include decorative finials unless the manufacturer specifically defines the rod width that way.
If you are measuring a rod, measure the usable pole length between the finials. For a new installation, the rod or track is often placed wider than the window so the curtains can stack beside the glass when open. This can make the window appear wider and allows more daylight into the room.
The final width of the fabric is not usually equal to the track width. Curtains need fullness so they form attractive folds when closed.
Width formula
Required fabric width = track or rod width × fullness factor
Typical starting points are:
|
Curtain style
|
Practical starting fullness
|
|
Light, relaxed curtain
|
1.5 to 1.75 times the fitting width
|
|
Standard gathered curtain
|
2 times the fitting width
|
|
Full, luxurious curtain
|
2.25 to 2.5 times the fitting width
|
The final factor depends on the fabric width, heading tape, pattern repeat, and the look you want. Heavy velvet may need a different treatment from a lightweight linen or sheer fabric.
Step 2: Measure the curtain length
Measure from the top of the installed track or rod to the desired bottom edge. Use the correct starting point for your heading. An eyelet curtain may begin below the top of the rod, while a track curtain usually starts from the track itself.
Choose one of these finishing styles:
Sill length: The curtain finishes slightly above the window sill. This is practical for a desk, radiator, or furniture placed under the window.
Below-sill length: The curtain extends below the sill for a more generous look without reaching the floor.
Floor length: The curtain finishes just above the floor, which is a clean choice for most living rooms and bedrooms.
Pooling length: The fabric extends onto the floor for a softer, more decorative appearance. This requires careful fabric and installation planning and may not be ideal in high-traffic areas.
Measure the drop in at least three places because floors, ceilings, and window openings are not always perfectly level. Use the smallest measurement if the curtain must finish neatly above the floor.
Step 3: Account for the curtain heading
The top of the curtain is affected by its heading. With a pencil-pleat heading, the hook position can change the visible drop. With eyelets, the fabric usually sits below the top of the rod. With a wave heading, the track and glider system must be compatible with the selected tape.
Do not order the finished length until you know how the curtain will be attached. If you are unsure, consult a curtain specialist before cutting fabric.
Step 4: Check the fabric width and pattern repeat
Curtain fabric is often sold by the metre, but the quantity depends on the fabric’s usable width. A large pattern repeat may require extra material so the design aligns across multiple panels. Directional prints may also affect how the fabric is cut.
When the material is narrow, the curtain may require multiple widths joined together. This is normal, but the seams should be planned so they look balanced when the curtains are closed.
Common measuring mistakes
The most common mistake is measuring only the window glass. Another is forgetting the space required for the rod, track, brackets, and curtain stack. People also frequently measure from the floor to the ceiling without deciding the actual top of the fitting.
Avoid rounding measurements too early. Keep the original numbers, state whether they are width or drop, and identify each window. For several windows, create a simple schedule with one row per opening.
When should you choose custom curtains?
Custom curtains are useful for unusually wide windows, bay windows, tall openings, layered treatments, special headings, or rooms where the finish must be precise. El Khawaga highlights curtain inspection, customization, and installation as part of its curtain service, so a measured consultation can reduce ordering errors.
You can also review Curtain Buying Guides and browse Curtain Rods or Tracks & Rails before finalising the fitting.
Final measuring checklist
Confirm the fitting width, finished drop, heading style, fullness factor, fabric width, pattern repeat, lining, and finishing point. Check the measurements again before ordering. If the project is valuable or technically difficult, arrange a professional inspection rather than relying on an estimate.
Accurate measuring does more than prevent a sizing mistake. It helps the fabric hang correctly, improves light control, and makes the finished room look intentional.
Frequently asked questions How to Measure Curtains
Should curtain width be the same as window width?
Usually no. The curtain width should be based on the rod or track, with additional fabric for fullness. Measuring only the glass often produces curtains that look flat or fail to cover the opening properly.
How much wider should curtains be than the window?
The answer depends on where the rod or track is installed and the desired fullness. A common starting point is approximately two times the fitting width for a standard gathered appearance, but the fabric and heading can change the calculation.
Should curtain length touch the floor?
Floor-length curtains normally finish just above the floor for a clean look. A small amount of pooling can be chosen for decoration, but it requires more maintenance and careful planning.
Do I measure curtains in centimetres or metres?
Either is acceptable, but use one unit consistently. Record the measurements clearly before converting them into the amount of fabric required.
Browse the Cushion Collection from ElkhawagaÂ
Don’t miss out on the opportunity to visit our El Khawaga Fabrics branches
