How rectangular pieces are arranged on a fabric roll
The calculator converts all dimensions to one internal unit, subtracts the edge allowance from both sides of the roll, and finds how many rectangular pieces fit across. Rows equal the requested piece count divided by pieces per row, rounded up. Required length includes every row, spacing between rows, both end allowances, and the selected extra-material percentage.
Compare entered and rotated orientations
Keeping the entered orientation places piece width across the roll. Rotating places piece length across the roll. The efficient option evaluates both all-one-direction layouts and chooses the one needing less roll length. It does not mix orientations within one row or solve irregular nesting.
Allow for grain, nap, repeats, shrinkage, and defects
This estimate assumes identical rectangular pieces on a straight roll. Directional prints, pattern repeats, grain or nap requirements, selvage, prewashing shrinkage, crooked cuts, defects, seams, irregular shapes, and supplier cut increments can require more fabric. Confirm the cutting plan before purchasing.