Fabric Calculator
Work out how many yards of fabric to buy. Enter the cut size of each piece in inches (seam allowance included), how many pieces you need, and the bolt width (36, 44/45, 54, or 60 in) — the calculator lays the pieces out in rows and rounds up to the quarter yard stores actually cut.
Example: with Piece width (in, cut size) 10 · Piece length (in, cut size) 10 · Number of pieces 20 · Fabric width 44/45 in (standard quilting cotton) → Yards to buy: 1.5 yd.
- With 10% cushion1.75 yd (covers prewash shrinkage and squaring up)
- Cutting layout4 pieces per row × 5 rows = 50 in of length
- Exact requirement1.39 yd (50 in)
Computed by the calculator below using its default values. Change any input to see your own numbers.
Pieces per row = floor(fabric width ÷ piece width); rows = ceil(pieces ÷ per row); yards = rows × piece length ÷ 36, rounded up to the quarter yard.
How yardage really gets counted
Fabric is sold by length off a bolt of fixed width, so the question is never just total area — it is how many of your pieces fit side by side across the bolt. The calculator divides the fabric width by your piece width and keeps the whole number: on 44-inch cotton, four 10-inch squares fit per row and the leftover 4-inch strip is scrap. It then stacks rows until you have enough pieces and converts the running length to yards (36 inches each).
That floor-then-stack logic is why a small change in piece width can swing yardage a lot. An 11-inch square drops you from 4 per row to 3 on 44-inch fabric — 25% more length for a piece only 10% bigger.
How it’s calculated
Pieces per row = floor(fabric width ÷ piece width). Rows = ceil(pieces needed ÷ pieces per row). Length needed = rows × piece length; yards = length ÷ 36, rounded UP to the next 1/4 yd (how US stores cut). The cushion result adds 10% before rounding, covering prewash shrinkage and squaring the cut ends.
Treats every piece as a straight-grain rectangle with no directional print, nap, or pattern repeat to match — matched prints need roughly one extra repeat length per row.
What one yard of 44/45 in fabric yields
| Cut piece | Per row | Per yard |
|---|---|---|
| 5 × 5 in charm square | 8 | 56 |
| 10 × 10 in layer-cake square | 4 | 12 |
| 18 × 18 in pillow front | 2 | 4 |
| 20 × 20 in napkin | 2 | 2 |
Computed with rows of whole pieces across a 44 in bolt and 36 in of length per yard; no pattern matching.
Common mistakes
- Entering finished sizes instead of cut sizes — add seam allowances to every edge before you calculate.
- Skipping the cushion: quilting cotton commonly shrinks 3-5% in the first wash, so prewash and buy the extra.
- Counting the full printed width — selvages trim 1-2 in off the usable width, which matters when pieces barely fit.
- Forgetting that directional prints and napped fabrics (velvet, corduroy) force every piece to face one way, wasting more.
Frequently asked questions
What is the fabric yardage formula?
Pieces per row = fabric width ÷ piece width, rounded down. Rows = pieces needed ÷ pieces per row, rounded up. Yards = rows × piece length ÷ 36, rounded up to the quarter yard.
How much seam allowance should I add?
Add the allowance to each edge before entering the piece size: 1/4 in per edge for quilting (a 10 in finished square cuts at 10.5 in) and 5/8 in per edge for most garment patterns.
Why round up to quarter yards?
US fabric stores cut in 1/4-yd increments (9 in). Rounding up also gives the cutter room to square off a crooked first cut.
Does this work for garments?
Use it for rectangles — quilt blocks, curtains, napkins, linings. Commercial garment patterns print their own yardage charts because curved pattern pieces interlock in ways simple rows cannot capture.