Sew Measure

Sewing calculator

Curtain Fabric Calculator: Yardage, Fullness, and Pattern Repeat

Estimate curtain yardage from track width, fullness, fabric width, header and hem allowances, and vertical pattern repeat.

Your measurements

Use one unit for every dimension in this form.

Finished span covered by the curtains.

Finished curtain length.

Flat fabric width divided by track width.

Usable width before side hems.

Amount used by each side hem.

Fabric above the finished drop.

Fabric used by the lower hem.

Enter zero for a solid or non-matched fabric.

Optional percentage added before cutting waste.

Optional percentage for layout and cutting waste.

Curtain fabric result

Full-width drops
4
Cut drop
92.00 in
Fabric to buy
10.250 yd
Curtain panelsA scaled planning diagram. Use the matching text result and cut list for exact dimensions.4 full-width dropsCut lengths
Curtain panels. The drawing is scaled for comparison; written dimensions control.

Formula

Track width times fullness sets flat width; usable panel width sets panel count; each cut drop includes hems and repeat matching.

Assumptions

  • The drop count is the total number of full fabric widths across the whole track, not the chosen number of finished curtains.
  • Fabric is railroaded only when the project explicitly permits it.
  • Hardware is outside this estimate.

When a tested commercial pattern gives different cutting dimensions or layout instructions, follow that pattern.

Worked example

  • 80 in track
  • 2× fullness
  • 54 in fabric with 2 in side hems
  • 80 in finished drop + 4 in header + 8 in bottom hem

Four full-width drops at 92 inches each require 368 inches before purchase rounding, so the calculator reports 10.25 yards with no extra shrinkage or waste.

Verification note

Measure the installed track and finished drop in several places before ordering fabric.

Learn and verify

Questions from search

How much fabric do curtains need?

Multiply track width by the fullness ratio, divide by usable fabric width to get the number of widths, then multiply cut drop by that count and convert to yards.

How does pattern repeat change curtain yardage?

Round each cut drop up to the next full vertical repeat before multiplying by the number of widths. That extra length is what matching the motif costs.