Quilt Yardage Formula: How to Calculate Fabric for Any Quilt

Updated: May 27, 2026

Three Separate Formulas

Calculating fabric for a quilt requires three separate calculations: quilt top, backing, and binding. Never combine them — the waste factors, fabric widths, and panel counts are different for each.

1. Quilt Top Formula

The quilt top is the patchwork face of the quilt. The formula is based on total area plus a waste allowance for seam allowances, directional cutting, and trimming.

Quilt area (sq in) = quilt width (in) × quilt length (in)
Area with waste    = quilt area × (1 + waste ÷ 100)
Total yards        = area with waste ÷ (usable fabric width × 36)
Yards per fabric   = total yards ÷ number of fabrics

Usable fabric width (WOF after removing selvages):

Bolt Width	Usable Width
44”	42”
42” (pre-washed)	40”
60”	58”

Waste factor guidelines:

Waste %	When to Use
10%	Solids, simple squares
15%	Standard patchwork (recommended)
20%	Directional prints, fussy cutting, half-square triangles
25–30%	Complex blocks with many bias cuts

Worked Example — Twin Quilt, 4 Fabrics

Quilt: 60” × 90”. 4 equal fabrics. 15% waste. 44” WOF (usable 42”).

Quilt area = 60 × 90 = 5,400 sq in
With waste = 5,400 × 1.15 = 6,210 sq in
sq per yard = 42 × 36 = 1,512
Total yards = 6,210 ÷ 1,512 = 4.11 yards
Per fabric  = 4.11 ÷ 4 = 1.03 yards → buy 1⅛ yards each

2. Backing Formula

The backing extends 4” beyond all quilt edges (8” total per dimension) for longarm quilting grip and trimming after quilting.

Backing width  = quilt width  + 8"
Backing length = quilt length + 8"
Panels         = ⌈backing width ÷ usable fabric width⌉
Backing yards  = (panels × backing length) ÷ 36

Add 1” per panel-to-panel seam for trimming allowance.

Panel count for 44” WOF (42” usable)

Quilt Width	Backing Width	Panels Needed
Up to 34”	Up to 42”	1 panel
35” – 76”	43” – 84”	2 panels
77” – 118”	85” – 126”	3 panels

Worked Example — Queen Quilt Backing

Quilt: 90” × 108”. 44” WOF backing fabric (42” usable).

Backing width  = 90 + 8 = 98"
Backing length = 108 + 8 = 116"
Panels = ⌈98 ÷ 42⌉ = ⌈2.33⌉ = 3 panels
Backing yards = (3 × 116) ÷ 36 = 348 ÷ 36 = 9.67 → buy 9¾ yards

Wide backing fabric (108”)

For a queen quilt (90” wide): backing width = 98”. 98 ÷ 106 usable = 0.92 → 1 panel. Yards = 116 ÷ 36 = 3.22 → buy 3¼ yards. Major savings over WOF.

3. Binding Formula

Double-fold binding is cut crossgrain (selvage to selvage) from 42” WOF fabric. The standard cut width is 2.25”, which yields a ¼” finished binding.

Quilt perimeter       = 2 × (quilt width + quilt length)
Total binding needed  = perimeter + 12"  (mitered corners + overlap)
Strips from 42" WOF   = ⌈total needed ÷ 42"⌉
Binding yards         = (strips × strip width) ÷ 36

Binding yardage by quilt size

Quilt Size	Perimeter	Strips (2.25” WOF)	Yards
Baby 36×45”	162”	5	0.375
Lap 50×65”	230”	6	0.375
Twin 60×90”	300”	8	0.5
Full 78×90”	336”	9	0.625
Queen 90×108”	396”	10	0.625
King 108×108”	432”	11	0.75

Rounding Rules

Always round up — never down. Round to the nearest ⅛ yard (0.125 yd), the smallest increment most fabric stores cut.

Round up rule: yards = ⌈(raw yards ÷ 0.125)⌉ × 0.125

Example: 0.92 yards → round up to 1.0 yard. 1.03 yards → round up to 1.125 yards (1⅛ yards).

Use the Quilt Fabric Calculator — enter size and fabrics for instant results.