Curtain Yardage Calculator

This calculator estimates the fabric needed to make curtains. Enter the rod width, the fullness you want, the finished length, the allowance for the hem and heading, and the width of your fabric; you get the yardage, the number of fabric widths to join and the cut length of each width.

Formula

Widths = rod width × fullness ÷ fabric width, rounded up. Cut length = finished length + hem and heading allowance. Yardage = widths × cut length ÷ 36.

• rw: rod or track width in inches
• fl: fullness, often 2 for gathered and pencil-pleat headings, 2.5 for pinch pleats, 1.5 for flat panels
• dl: finished drop from the rod to the hem
• ha: extra fabric for the hem and heading together, as your pattern states
• fw: usable fabric width from the bolt label

Worked Example

A 60 in rod, fullness 2, an 84 in drop, a 16 in allowance and 54 in fabric.

1. Widths = 60 × 2 ÷ 54 = 2.22, rounded up to 3 widths
2. Cut length = 84 + 16 = 100.0 in
3. Yardage = 3 × 100 ÷ 36 = 8.33 yd
4. In metres: 3 × 100 × 0.0254 = 7.62 m

How to read the result

Split the widths between the two curtains (here one and a half widths each, cut one width down the middle). Buy a little extra for straightening the cut ends and, for patterned fabric, add one pattern repeat per width so the pattern lines up across the seams.

Limits and common mistakes

• The allowance depends on the heading tape and hem depth; use your pattern’s figure.
• Patterned fabric needs extra for matching repeats; this calculator does not add it.
• Measure the rod, not the window, and include any return to the wall if the curtain wraps round.

Frequently Asked Questions

How much fullness do curtains need?

Usually 1.5 to 2.5 times the rod width, depending on the heading style.

How many yards for two 84 inch curtains?

With a 60 in rod, fullness 2, a 16 in allowance and 54 in fabric, about 8.33 yd.

Does fabric width change the yardage?

Yes. Wider fabric needs fewer widths, which can save a whole cut length.

What about pattern repeats?

Add one repeat to each cut length so the pattern matches.

in rw | Rod width | in | 60 | 1 | 1000
in fl | Fullness (times rod width) | × | 2 | 1 | 4
in dl | Finished length (drop) | in | 84 | 1 | 400
in ha | Hem and heading allowance | in | 16 | 0 | 60
in fw | Fabric width | in | 54 | 10 | 150
out yd | Fabric to buy | yd | ceil(round(rw * fl / fw, 6)) * (dl + ha) / 36 | 2
out widths | Fabric widths (drops) | widths | ceil(round(rw * fl / fw, 6)) | 0
out cut | Cut length of each width | in | dl + ha | 1
out m | Fabric to buy | m | widths * cut * 0.0254 | 2