How does this fabric calculator arrange the pieces?

It sorts pieces by cut height, then cut width, then input order. Each piece goes into the first existing row that fits, trying its original orientation before a permitted turn. A new row uses the feasible orientation with the smaller row height. This deterministic shelf method does not prove a minimum fabric length.

Does the seam allowance change both dimensions?

Yes. Twice the allowance is added to both the entered width and height. A 10 by 10 inch piece with a 0.5 inch allowance per edge becomes an 11 by 11 inch cut. Four such cuts on 40 inch usable fabric occupy two rows, use 22 inches of length and leave 396 square inches of unused area.

What does the grain lock do?

A locked piece keeps its entered height along the fabric length and cannot rotate. To permit a 90 degree turn, first unlock its grain, then enable rotation. The diagram and coordinate table show the orientation chosen for each copy.

What width should I enter?

Enter the usable width after excluding selvage. The planner does not subtract another selvage margin. It treats the available fabric as a continuous rectangle and does not account for defects, pattern matching, shrinkage or stretch.

What does the waste percentage measure?

Waste is the usable width multiplied by the planned length, minus the area of all cut pieces. The percentage divides that unused area by the same used-fabric rectangle. Fabric farther along the uncut roll is outside this calculation.

Can I use inches, centimetres or millimetres?

Yes. Changing units preserves the physical dimensions, including seam allowance. Inputs accept decimal numbers and fractions such as 1/2. Some exact conversions appear as fractions. Very fine or very large dimensions that exceed coordinate precision receive an explicit unresolved message.

What happens when the calculation is too large or I cancel it?

Packing runs in a background worker and can be cancelled or replaced by editing the inputs. Requests that exceed the coordinate or search budget remain unresolved, with no partial layout presented as complete. Entered rows stay available so the request can be adjusted or split into smaller runs.

Can I print or save the cutting plan?

A completed plan can open in a print tab or download as an original SVG. Both include the rows, cut sizes, quantities, grain orientations and totals. The on-screen preview shows one row and up to 100 pieces at a time; completed exports include every piece. Export memory exhaustion is reported explicitly without truncating the plan.

Are my dimensions remembered?

Edited input rows and dimensions are saved in this browser when local storage is available. A restored draft does not calculate automatically, and calculated layouts are not saved. Choose Plan rows to run the restored dimensions.

Fabric Cutting Planner

Enter a usable fabric width and rectangular piece sizes to build a row-by-row cutting plan. Set quantities, add seam allowance to each edge, and allow rotation only where the piece grain permits it. The completed layout shows every requested piece, used length, yardage and unused area within that length.

Usable width (in)Seam allowance per edge (in)

Usable width already excludes selvage. Enter finished piece sizes; the seam allowance is added on both edges. Decimals and fractions such as 1/2 are accepted.

Piece	Width (in)	Height (in)	Quantity	Rotate 90°	Grain	Remove
				Allow	Lock ↕

A grain lock keeps the piece height along the fabric length. Unlock grain before allowing a 90° turn.

Cutting layout

Awaiting a complete plan

Your row-by-row plan appears hereChoose Plan rows to place every requested rectangle and check the used length and waste.

Example dimensions are ready. Choose Plan rows to calculate a cutting layout.

Worked examples

Exact row40 in width; four 10 × 10 in; seam 0
10 in length; 0 in² waste
Seam on every edge40 in width; four 10 × 10 in; seam 0.5 in
Four 11 × 11 cuts; 2 rows; 22 in; waste 396 in² = 45%
No feasible orientation40 in width; 41 × 10 in; rotation off
Infeasible: piece is wider than fabric

Accuracy. Heuristic rectangular packing, not a proof of minimum fabric or a guarantee for patterned/stretch materials.

Common questions

How does this fabric calculator arrange the pieces?: It sorts pieces by cut height, then cut width, then input order. Each piece goes into the first existing row that fits, trying its original orientation before a permitted turn. A new row uses the feasible orientation with the smaller row height. This deterministic shelf method does not prove a minimum fabric length.
Does the seam allowance change both dimensions?: Yes. Twice the allowance is added to both the entered width and height. A 10 by 10 inch piece with a 0.5 inch allowance per edge becomes an 11 by 11 inch cut. Four such cuts on 40 inch usable fabric occupy two rows, use 22 inches of length and leave 396 square inches of unused area.
What does the grain lock do?: A locked piece keeps its entered height along the fabric length and cannot rotate. To permit a 90 degree turn, first unlock its grain, then enable rotation. The diagram and coordinate table show the orientation chosen for each copy.
What width should I enter?: Enter the usable width after excluding selvage. The planner does not subtract another selvage margin. It treats the available fabric as a continuous rectangle and does not account for defects, pattern matching, shrinkage or stretch.
What does the waste percentage measure?: Waste is the usable width multiplied by the planned length, minus the area of all cut pieces. The percentage divides that unused area by the same used-fabric rectangle. Fabric farther along the uncut roll is outside this calculation.
Can I use inches, centimetres or millimetres?: Yes. Changing units preserves the physical dimensions, including seam allowance. Inputs accept decimal numbers and fractions such as 1/2. Some exact conversions appear as fractions. Very fine or very large dimensions that exceed coordinate precision receive an explicit unresolved message.
What happens when the calculation is too large or I cancel it?: Packing runs in a background worker and can be cancelled or replaced by editing the inputs. Requests that exceed the coordinate or search budget remain unresolved, with no partial layout presented as complete. Entered rows stay available so the request can be adjusted or split into smaller runs.
Can I print or save the cutting plan?: A completed plan can open in a print tab or download as an original SVG. Both include the rows, cut sizes, quantities, grain orientations and totals. The on-screen preview shows one row and up to 100 pieces at a time; completed exports include every piece. Export memory exhaustion is reported explicitly without truncating the plan.
Are my dimensions remembered?: Edited input rows and dimensions are saved in this browser when local storage is available. A restored draft does not calculate automatically, and calculated layouts are not saved. Choose Plan rows to run the restored dimensions.

Heuristic rectangular packing, not a proof of minimum fabric or a guarantee for patterned/stretch materials.