How the calculator works
Fabric is cut the way quilt patterns write their cutting lists. First you cut strips across the fabric, selvage to selvage. Then you cut the strips into pieces. For each piece size the calculator works out:
- Pieces per row = usable fabric width ÷ piece width, rounded down.
- Rows = pieces needed ÷ pieces per row, rounded up. Each row is one strip cut across the fabric.
- Length = rows × piece length.
Lengths for all your piece sizes are added together. Any shrinkage allowance is added, and the total is rounded up to the next ⅛ yard and the next 10 cm.
Turning pieces. If the pieces can be turned 90°, the calculator lays them out both ways and keeps the one that uses less fabric. Turn this off for one-way prints, napped fabrics like velvet and corduroy, or garment pieces whose grainline has to run along the length.
Several piece sizes. Each size gets its own strips, so leftovers at the end of one size's strips are never counted toward another. That is how most people cut, and it keeps the answer on the safe side. A careful layout can sometimes fit small pieces into those leftovers.
Shrinkage. The allowance is added to the length. If you need 36 inches after a 5 percent shrink, you buy 36 ÷ 0.95 = 37.9 inches. Washing narrows the fabric too, so if your pieces only just fit across, measure the width after washing.
How many pieces fit in a yard
Pieces cut from 42-inch fabric, laid out the best way round. Strips run the full width of the fabric.
| Cut | ¼ yard (9 in) | ½ yard (18 in) | 1 yard (36 in) |
|---|---|---|---|
| 1 ½ in strips | 6 | 12 | 24 |
| 2 ¼ in binding strips | 4 | 8 | 16 |
| 2 ½ in strips (jelly-roll size) | 3 | 7 | 14 |
| 2 ½ in squares | 48 | 112 | 224 |
| 3 ½ in squares | 24 | 60 | 120 |
| 5 in charm squares | 8 | 24 | 56 |
| 6 ½ in squares | 6 | 12 | 30 |
| 10 in squares (layer-cake size) | – | 4 | 12 |
| 12 ½ in squares | – | 3 | 6 |
Because rows are rounded down, a half yard does not always give half of what a yard gives. Only three 5-inch rows fit in 18 inches but seven fit in 36, so a half yard gives 24 charm squares, not 28.
Example: squares and binding from one fabric
A quilt needs thirty 6 ½-inch squares and eight 2 ½-inch binding strips from the same 42-inch cotton.
- Squares: six fit across (6 × 6 ½ = 39 inches, 3 inches left over). Thirty squares ÷ 6 = 5 strips 6 ½ inches deep = 32 ½ inches.
- Binding: each strip is the full width, one per row: 8 strips × 2 ½ inches = 20 inches.
- Total: 32 ½ + 20 = 52 ½ inches = 1.46 yards. Buy 1 ½ yards (1.4 m).
If you prewash and allow 5 percent for shrinkage, 52 ½ inches becomes 55.3 inches, and the cut goes up to 1 ⅝ yards.
Example: turning pieces saves fabric
You need twelve pieces of 9 × 14 inches from 42-inch fabric.
- Upright (9 inches across): 4 fit across with 6 inches wasted. Three rows of 14 inches use 42 inches, so you buy 1 ¼ yards.
- Turned (14 inches across): 3 fit across exactly. Four rows of 9 inches use 36 inches, so you buy 1 yard.
Turning the pieces saves a quarter yard. On a one-way print, though, the turned pieces would have the design running sideways.
Tips before you buy
- Enter cut sizes. Include the seam allowances: a square that finishes at 6 inches is cut at 6 ½.
- Garment pieces are not rectangles. For a pattern piece, enter its longest and widest measurements. Real pieces nest together, so the yardage on the pattern envelope, which comes from an actual layout, is usually less than this estimate.
- Buy everything at once. Bolts printed or dyed at different times can differ slightly in color.
- Square up before cutting. Fold the fabric selvage to selvage, line up the fold, and trim the cut end straight. That trim comes out of your yardage.
- Match large prints. For curtains or a print you want to line up across seams, add one pattern repeat per extra panel or piece.
Frequently asked questions
How do I calculate how much fabric I need?
Divide the fabric width by the piece width and round down to get pieces per row. Divide the number of pieces by that and round up to get rows. Multiply the rows by the piece length and divide by 36 for yards, then round up to the next ⅛ yard. Try the pieces turned sideways too and keep whichever uses less.
How many 5-inch squares can I cut from a yard of fabric?
56 from a yard of 42-inch fabric. Eight squares fit across the width and seven rows fit in the 36-inch length. A half yard gives 24, because only three 5-inch rows fit in 18 inches.
How many 2 ½-inch strips are in a yard of fabric?
Fourteen strips cut across the width of the fabric. 36 ÷ 2 ½ is 14.4, and the leftover 1 inch is too narrow for another strip. A half yard gives seven.
What is the usable width of 44-inch fabric?
Less than 44 inches once the selvages are trimmed, and it varies by mill. Quilt pattern designers often assume 40 or 42 inches of usable width for quilting cotton. Measure your fabric between the selvages and enter that as a custom width if it matters.
Should I buy extra fabric?
A little. Shop cuts are not always straight, and squaring up the end uses some of the length. Prewashing shrinks the fabric, and a cutting mistake needs a spare. Many sewists add ⅛ to ¼ yard, and more for prints with a large repeat to match.
How much does fabric shrink when washed?
It depends on the fiber and the weave. Quilting cotton commonly shrinks around 3 to 5 percent. To know for sure, measure a swatch, wash and dry it the way you will wash the finished piece, and measure again. Enter that percentage as the shrinkage allowance.
Last updated October 17, 2026.