How to Measure for Curtains: Width and Length

This is general home-living information. Follow product labels, manuals, lease rules, local requirements, and qualified advice for electrical, plumbing, structural, gas, pest, mold, ladder, medicine, or installation work.

Decide where the curtain will hang and where its lower edge should finish before choosing a size. Record the usable rod or track span, the total fabric width required by the chosen heading style, and the finished drop from its actual hanging point. Window-glass width alone cannot answer all three questions.

Use the intended curtain and hanging-system instructions alongside your measurements. A ready-made panel, a made-to-measure curtain and a roller blind may ask for different information. This guide concerns fabric curtains; do not apply its worksheet as a blind-ordering specification.

Three measurements that decide the order

1. Usable rod or track span: measure the operating span requested by the chosen system, not only the window glass.
2. Fabric width: use the heading and supplier’s ordering method; confirm whether the listing describes one panel or a pair.
3. Finished drop: measure from the actual hanging point to the intended lower edge using the product’s diagram.

Keep those labels on your notes. A number without its measuring origin or width definition is not enough to place a reliable order.

Start with how the window opens

Open the window and check the positions of its handles, sill and nearby furniture. Look at the wall or ceiling space available for the intended system. Consider whether the curtains need to clear the glass when open, cover it for privacy when closed or stop above a feature below the window.

These are use decisions, not simply styling choices. A desk beneath a window may make one finishing point more practical than a floor-length curtain. A nearby heater may impose restrictions that must come from its instructions. Do not let a general length recommendation override equipment clearances.

If a mounting position is uncertain, settle that question before ordering the fabric. A rented home may have limits on drilling or alterations, and a wall or ceiling may need suitable assessment for the chosen load and fixing method.

Separate the rod span from the fabric width

The rod or track span describes the space over which the curtains operate. The fabric width describes how much material is needed for the finished arrangement. They are related but are not interchangeable measurements.

Include the space required for the chosen system and for opening the curtains. How much space a gathered curtain occupies when drawn back depends on the material, heading and installation. Check the product instructions rather than assuming the window frame defines the complete arrangement.

IKEA's curtain measuring guide distinguishes rod or rail width, fabric width for the chosen pleated effect and the final length. Its dimensions are guidance for those arrangements, not a universal specification for every curtain system.

When the seller asks for a fullness ratio, use the ratio specified for that product and heading. If it asks for finished width instead, follow that ordering method. Do not multiply a measurement again merely because a generic guide mentions fullness.

An illustrative panel calculation

Suppose the usable span is 180 cm and the selected product's instructions call for total flat fabric width equal to twice that span. The resulting total would be 360 cm. With two equal panels, each would contribute 180 cm of flat width. These numbers illustrate the calculation only; twice the span is not a recommendation for every fabric or heading.

Check whether the listing's width is for one panel or a pair. Confirm whether that number describes flat fabric, gathered width or finished width. A correct calculation using the wrong type of listing measurement still produces the wrong order.

Measure length from the actual hanging point

Identify the point from which the product's finished drop is measured. A hook, ring, eyelet and concealed heading can place the curtain's top and hanging point differently. Follow the seller's diagram; do not assume the top of the rod is the right starting point.

Then choose the lower finishing point. Write the measured drop beside that choice. If the floor varies across the intended span, record that variation and ask the supplier how it should be handled. Avoid silently averaging away a difference that could cause one end to drag.

Check the care instructions before deciding on hemming or alterations. Fabric behaviour, washing instructions and the seller's alteration guidance matter. Do not add a guessed shrinkage allowance to an order that already includes the supplier's allowance.

Keep a short order worksheet

Photograph the window and keep the product diagram with the worksheet. That makes a question to the supplier easier to answer than a message saying the curtains need to be “standard size.”

Check safety before the installation decision

Where young children live or visit, consider the cord hazards of the complete window-covering arrangement, including an existing blind behind the fabric curtain. The US Consumer Product Safety Commission recommends cordless window coverings when young children are present. Curtain styling does not remove a hazard from another covering.

For mounting, follow the exact hardware and surface requirements. This worksheet is not a load calculation or a fixing instruction. Get suitable help when the surface, load or installation method is uncertain.

Before placing the order

Read the measurements back in the supplier's terms. Confirm the quantity of panels, whether accessories are included and how the finished length is defined. Recheck current return terms, particularly when the order is made to measure or altered.

Keep the result alongside other room decisions rather than expanding it into a complete renovation. If nearby furniture is part of the conflict, use the furniture measuring guide. If you are choosing a floor covering at the same time, keep its dimensions in the separate rug sizing worksheet.