The pattern tells you, in a table indexed by size, view and fabric width — read the right cell rather than the first number you see.
Width matters as much as length. The same garment needs considerably more length from 110 cm fabric than from 150 cm, because fewer pieces fit side by side. Check the width on the bolt before buying, not the width you assumed.
Take the with-nap figure for corduroy, velvet, brushed fabric, one-way prints and anything with a directional weave. All the pieces must run the same way, which uses more cloth. If you are unsure, buy the with-nap quantity — it is the safer error.
Add for the things the table does not cover. Shrinkage, if you have not prewashed: allow a little extra on cotton and linen. Pattern matching on checks, stripes and large prints, which can add a repeat’s worth of length per piece. Lengthening adjustments. Fussy cutting to place a motif.
Subtract nothing. The table already assumes an efficient layout.
When there is no table — a self-drafted pattern or a rescued piece — lay the paper pieces out on the floor at the fabric width, in the arrangement you will actually cut, and measure the length they occupy. It takes fifteen minutes and it is the only reliable method.
Buy the trimmings at the same time. Interfacing, lining, zip, thread and buttons. Returning for a second attempt at a colour match rarely goes well.
Questions people actually ask
How much extra should I allow for shrinkage?
Prewash instead — it removes the guesswork entirely. If you cannot, allow a modest extra length on natural fibres, which shrink most.
Does the table allow for pattern matching?
No. Checks, stripes and large repeats need extra, roughly one pattern repeat for each piece that must match.
Last reviewed 2026-08-11