Curtain Size Lab Search

FABRIC GUIDE · REVIEWED SEPTEMBER 11, 2026

How Much Fabric Do I Need for Curtains?

Calculate fabric widths, cut length, pattern-repeat adjustment, yards, meters, and an editable contingency.

MEASURED WIDTHFINISHED DROP
Original proportional diagram. Use actual measurements; drawing is not to scale for a specific product.

SHORT ANSWER

Start here

Fabric yardage equals the required number of full fabric widths multiplied by the adjusted cut length, plus pattern-match and contingency allowances. The correct result depends on finished width, panel count, fabric width, repeat, heading and hem allowances, match type, and whether the design can be railroaded.

Width countRound up per panel
Cut lengthDrop + heading + hem
Patterned clothRound to repeat
OutputYards + meters

How to measure

  1. 01

    Measure the actual working rod or track width; if hardware is not installed, record the window-frame width and your planned side extensions separately.

  2. 02

    Measure the drop from the reference point stated for the selected heading—not from an unrelated edge of the window.

  3. 03

    Check whether a package contains one panel or a pair, then compare total flat fabric width rather than the label width alone.

  4. 04

    Recheck the selected product, tape, hooks, carriers, and fabric before ordering or cutting.

Count whole drops

Conventional vertical construction uses full fabric widths side by side. Divide each panel’s cut width by usable fabric width and round up, then multiply by panel count.

Pattern repeat changes every cut

A straight match rounds cut length up to a whole repeat. A half-drop can shift alternating widths by half a repeat; the calculator exposes that additional planning amount.

Railroading changes the orientation

If the design and fabric supplier allow it, wide fabric may run sideways so roll length supplies curtain width. The finished drop plus allowances must fit inside the usable fabric width.

Before you order or cut

Measure the actual window and selected product. Finished sizes, fullness, header take-up, hardware geometry, and manufacturer tolerances vary. Fabric can shrink, stretch, or behave differently by composition. Measurements do not guarantee fit, privacy, water containment, installation, load capacity, or structural safety. Use the selected product instructions, and have a professional workroom verify expensive custom-fabric orders.

SOURCE NOTES

What this page is based on

Measurements here combine mathematical results with labeled commercial conventions and design recommendations. Disagreements are kept as ranges rather than averaged into a false standard.

  1. Repeats and drapery yardageFabric for Home · reviewed 2026-09-11

    Fabric-supplier guide defining vertical repeat and separating plain-fabric yardage from repeat-adjusted drapery calculations.

  2. How to use the Sailrite fabric calculatorSailrite · reviewed 2026-09-11

    Fabric supplier calculator guidance covering project dimensions, fabric width, quantity, layout, and pattern-repeat matching.

  3. Made-to-measure curtain fabric specification exampleJohn Lewis & Partners / William Morris At Home · reviewed 2026-09-11

    Commercial specification example listing 139 cm fabric width, 49 cm repeat, and straight match; shows why the selected fabric data must be used.