Fabric planning guide
How to calculate fabric yardage
A transparent way to estimate fabric for repeated rectangular pieces before you cut.
Start with the finished size of one piece, the number of matching pieces, and the width of the fabric roll. Then account for the seam allowance, unusable selvage, print repeat, and a waste allowance that suits the project.
1. Add seam allowance to both edges
If the finished piece is 30 cm wide and needs 1.5 cm seam allowance on each edge, the cut width is 30 + (2 × 1.5) = 33 cm. Apply the same rule to the length. Enter the allowance per edge, not the combined total.
2. Find the usable fabric width
Selvage can be unsuitable for a finished piece. Subtract the loss on both sides of the roll: a 150 cm roll with 2 cm lost per side has 150 − (2 × 2) = 146 cm of usable width.
3. Count pieces across and rows down
Divide usable width by cut width and take the whole number that fits. For 33 cm pieces on 146 cm usable fabric, four fit across. Twelve pieces need three rows. The calculator also tests the 90-degree orientation when rotation is allowed.
4. Include repeat and waste
If the fabric has a vertical repeat, each cutting row is rounded up to a whole repeat. The base length is rows multiplied by that adjusted row length. A 10% waste allowance multiplies the base by 1.10; it is a planning buffer, not a guarantee.
Common mistakes to avoid
- Adding seam allowance only once instead of on both edges.
- Using the full roll width when the selvage will be removed.
- Forgetting that a pattern repeat can increase every cutting row.
- Treating a row estimate as an optimized plan for irregular shapes or directional fabric.
Check shrinkage, nap, print direction, defects, and the supplier's minimum cut increments. For complex or expensive fabric, confirm the plan with a knowledgeable cutter.