How does grain line affect fabric layout?

When grain line is required, pattern pieces must be placed parallel to the selvedge (lengthwise grain). This means pieces cannot be rotated to fit more efficiently, which typically uses more fabric but ensures the garment drapes correctly.

Should I add seam allowance before or after layout?

Add seam allowance to each piece before planning the layout. This calculator adds seam allowance automatically to the dimensions you enter. The default 1.5cm seam allowance is added to all edges of each piece.

What is a good fabric utilisation percentage?

Professional pattern layouts achieve 80-90% utilisation. Home sewers typically get 65-80%. Below 60% suggests the fabric width may not suit the pattern pieces. Wider fabric or rearranging pieces can improve utilisation.

How much extra should I add for shrinkage?

Cotton typically shrinks 3-5%, linen 5-10%, and synthetics less than 1%. Pre-washing fabric before cutting eliminates this concern. This calculator adds a shrinkage allowance to the total fabric length.

SewCalcs

Pattern Layout Optimizer — Fabric Cutting Layout

Optimize fabric cutting layout to minimise waste and calculate minimum fabric length needed.

Fabric Width

Width measurement

Number of Pattern Pieces

Pattern size or specification

Grain Line Required

Prevents rotating pieces

Piece Dimensions (length x width, cm)

Piece 1 Length

Length measurement

Piece 1 Width

Width measurement

Piece 2 Length

Length measurement

Piece 2 Width

Width measurement

How We Calculate This

This calculator estimates the minimum fabric length by packing pattern pieces into rows across the fabric width, accounting for seam allowance and shrinkage.

The approach

Each piece is sized with seam allowance, then packed into rows across the fabric width.

Utilisation = Total piece area ÷ Total fabric area × 100

Frequently Asked Questions

Last updated: March 2026

All calculations are estimates. Always verify quantities before cutting or purchasing fabric.