How to measure for curtains

Start with the installed rod or track

For a curtain-width calculation, measure the usable span of the rod or track that the curtains will cover. Leave decorative finials out of that number. A window-frame measurement and a rod measurement describe different things; do not enter one as the other.

If the hardware is not installed, plan its position first and label the width as a proposed measurement. Make sure there is room for the curtain to sit beside the glass when open. Follow the hardware maker’s mounting instructions.

Keep extra coverage separate

A return is the part of a curtain that reaches back toward the wall at an outer edge. Center overlap is extra combined coverage where two curtains meet. These are separate from the rod span.

Our panel calculator adds the two outer returns and one total center-overlap allowance before applying fullness. Leave an allowance at zero when it is not part of your plan. If you already included it in your width measurement, do not add it a second time.

Measure the finished drop from the right place

Choose where the curtain will hang and where you want its bottom edge to finish. Rings, hooks, tabs, and pockets can put the top of the fabric at different heights. Use the starting point specified for your chosen heading and hardware.

Measure at more than one point and write down any difference. Decide how to handle an uneven floor before cutting. The finished drop is the intended hanging length; heading and hem allowances are entered separately in the fabric calculator.

Record a useful shopping note

A few clear labels now make it much easier to compare products later. Keep every dimension in one unit while measuring.

• Room and window name.
• Rod or track span, excluding finials.
• Return at each outer edge and total center overlap, if used.
• Finished drop and the point it was measured from.
• Heading style and whether the curtains open from the center.

Buying panels or making them?

For ready-made curtains, use the panel calculator with the flat width of one panel and the number of panels in a package. Check the listing carefully if the width is described as gathered, pleated, or a pair.

For sewing, switch to the fabric calculator. It estimates plain face fabric cut in vertical drops for a pencil-pleat plan. Pattern matching, lining, and other headings need a different calculation.