Fabric Yardage Calculator
Need to cut a bunch of rectangles? Enter the piece size and count to find out how much fabric to buy.
Tip: use URL parameters, e.g. ?pieceWidth=4.5&pieceLength=4.5&pieceCount=100.
How the yardage estimate works
This calculator uses a simple nesting layout: it works out how many pieces fit across your fabric's usable width, then stacks the rows to find the length needed.
Step 1: pieces per row. Divide the fabric width by the piece width and round down. For 4.5" squares on 42" fabric, that's 9 pieces across.
Step 2: rows needed. Divide the total count by the pieces per row and round up. 100 pieces ÷ 9 = 12 rows.
Step 3: length and yardage. Multiply rows by piece length (12 × 4.5 = 54 inches), add a waste allowance for squaring and mistakes, and divide by 36.
This assumes you can nest pieces edge-to-edge with no gaps. For fussy cutting, directional prints or irregular shapes, add more waste or plan each layout individually.
What each input means
- Piece width and length (inches) — the cut size of each piece, including seam allowance. If a pattern says a 5" finished square, you enter 5.5" (or whatever your cut size is), not 5".
- Number of pieces — the total number of rectangles you need. If you're cutting multiple fabrics, run the numbers per fabric with its own count.
- Fabric width (usable) — the cutting width after selvedges. For 44"–45" quilting cotton, that's about 42".
- Waste allowance (percent) — extra fabric for squaring up the fabric edge, selvedge loss and re-cuts. Ten percent is a reasonable default; use more for directional or fussy-cut layouts.
When to use it. Use this calculator whenever you're cutting a batch of identical rectangles: charm squares from a yard of fabric, strips for a border, or rectangles for a rail-fence block. It's most valuable before you buy, because the answer tells you whether one yard is enough or you need to round up to the next sellable cut. Before you calculate, decide whether your pieces can be nested side by side; if you plan to fussy-cut motifs, cut on the bias, or work with a directional print, raise the waste allowance so the estimate stays honest. And if the count is large, double-check the pieces-per-row number: even a half-inch difference in piece width can change how many fit across, which shifts the yardage by a whole row.
Common mistakes to avoid
- Entering finished sizes instead of cut sizes. The calculator can't know your seam allowance, so be consistent and use the size you'll actually cut.
- Using the full 44" width. Selvedges aren't usable; entering 44" instead of 42" can undercount by a full row.
- Forgetting to round rows up. If 100 pieces need 12 rows, buying for 11 rows leaves you short — the calculator rounds up for you.
- Assuming perfect nesting. Triangles, diamonds and oddly shaped pieces waste fabric. For those, add extra waste or use a tool designed for the shape.
- Ignoring directional prints. One-way designs can't be rotated for nesting, which usually means a whole extra repeat or strip.
Frequently asked questions
How many 5-inch squares in a yard of fabric?
From 42"-wide fabric, you can cut 8 squares across (5.5" with seams = 44 > 42, so 7-8 depending on method). A yard gives about 56-64 five-inch squares using strip cutting.
Should I include seam allowance in the piece size?
Yes — enter the cut size, which is the finished size plus seam allowances. The calculator assumes you've already added them.
What's a reasonable waste allowance?
Ten percent covers squaring up and minor mistakes. For directional prints or complex layouts, use 15-20%.
Can I cut triangles with this calculator?
Not directly — triangles have different nesting. Use it for squares and rectangles; for HSTs, use our half-square triangle calculator.