Precut Fabric Calculator
Enter the square size you want to cut and how many you need. The calculator tells you how many fit across the fabric, how many yards to buy, and how many fat quarters that equals.
Tip: use URL parameters to pre-fill, e.g. ?squareSize=5&squareCount=60.
How precut math works
Divide the usable fabric width (42 inches) by your square size and round down to get the number of squares across one strip. Divide the count you need by that number and round up to get the number of strips, then multiply by the square size and divide by 36 for yards.
For fat quarters, the same idea uses the 18 x 22 inch rectangle: squares across times squares down. A 5-inch charm square yields 3 x 4 = 12 squares per fat quarter.
Common precut sizes
| Precut | Size | Approx. per yard (42") | Per fat quarter |
|---|---|---|---|
| Mini charm | 2.5" | 210 | 56 |
| Charm pack | 5" | 56 | 12 |
| Layer cake | 10" | 12 | 2 |
| Jelly roll strip | 2.5" x WOF | 14 strips | n/a |
What each input means
Square size: the cut size of the square before any seam allowance. For finished squares, add 1/2 inch first.
Squares needed: how many squares your project requires. The calculator rounds up to whole strips and whole fat quarters.
Common questions
Is a layer cake exactly 10 inches?
Layer cakes are cut at 10 inches before any seam allowance, so they finish at 9.5 inches in a quilt. The same rule applies to charm squares and other precuts.
How many jelly roll strips make a quilt?
A typical jelly roll has 40 strips, enough for a modest lap quilt when sewn into a strip set. The exact count depends on your pattern and finished size.
Should I add fabric for shrinkage with precuts?
Precuts are usually not prewashed by the manufacturer, so they can shrink in your first wash. Add 3-5% to your yardage estimate if you plan to wash the finished quilt.
Can I use this for triangles or rectangles?
This calculator handles squares. For rectangles, split the piece into its dimensions and use the fabric yardage calculator on this site.