Fabric Yardage

Calculating How Much Fabric You Need

Fabric needed is how many rows of pieces you need, times each piece’s length, plus a waste margin. Enter how many pieces you need, each piece’s dimensions, your fabric’s bolt width, and a waste margin.

The Formula

$$\vE{\text{Pieces per Row}} = \left\lfloor \frac{\vD{\text{Bolt Width}}}{\vB{\text{Piece Width}}} \right\rfloor$$ $$\vF{\text{Rows Needed}} = \left\lceil \frac{\vA{\text{Pieces Needed}}}{\vE{\text{Pieces per Row}}} \right\rceil$$ $$\vG{\text{Total Length}} = \vF{\text{Rows Needed}} \times \vC{\text{Piece Length}} \times (1 + \vH{\text{Waste \%}} / 100)$$

Worked Example

10 pieces of 60 cm × 40 cm, from a 112 cm-wide bolt, with a 10% waste margin:

1. Pieces per row: $\vE{\text{Pieces per Row}} = \lfloor 112 \div \vB{40} \rfloor = \vE{2}$.
2. Rows needed: $\vF{\text{Rows Needed}} = \lceil \vA{10} \div \vE{2} \rceil = \vF{5}$.
3. Total length: $\vG{\text{Total Length}} = \vF{5} \times \vC{60} \times 1.10 = \vG{330} \text{ cm}$.

Key Factors to Consider

• Directional prints, plaids, and patterns that need matching across pieces typically need extra fabric beyond the standard waste margin. A one-directional print (where every piece must face the same way) or a pattern that needs to align across a seam wastes more fabric per cut than a non-directional print — a higher waste margin (sometimes well beyond 10%) is reasonable for these cases.
• Fabric with a nap (like velvet or corduroy) also requires directional cutting. Nap fabrics reflect light differently depending on which way the fibers lay, so every pattern piece needs to be cut facing the same direction — treat this the same as a directional print for planning purposes.
• Pre-washing fabric before cutting can change its final dimensions. Many fabrics shrink somewhat when washed — if a project calls for pre-washing (common for garments that will be laundered later), buy fabric based on its pre-shrunk dimensions, or account for expected shrinkage in the yardage calculation.
• A pattern’s own yardage requirement, if you have one, is usually more accurate than a from-scratch calculation. Commercial sewing patterns typically print their own recommended yardage per size and fabric width on the envelope — use that figure directly when available, and reserve this calculator for custom projects without a pre-made pattern.

Common Mistakes

• Forgetting seam allowance in each piece’s dimensions. As with any cutting calculation, the piece dimensions entered here should already include whatever seam allowance your pattern or project calls for — entering only the finished size will come up short once pieces are actually sewn together.
• Assuming pieces always fit the bolt width in one orientation only. Rotating a piece 90 degrees sometimes fits more copies across the same bolt width (or fits at all, for a piece wider than the bolt in its original orientation) — worth checking both orientations by hand for an unusually shaped piece, since this calculator assumes a single fixed orientation.
• Using too small a waste margin for a directional print or plaid. As covered above, matching a pattern across a seam or keeping a one-directional print facing the same way both waste more fabric per cut than a plain, non-directional fabric — the standard ~10% margin is really a baseline for simple, non-directional cutting.
• Ignoring pre-wash shrinkage until after the fabric is already cut. As noted above, many fabrics shrink somewhat when laundered — buying exactly the raw calculated yardage for a project that will be pre-washed can leave too little fabric once shrinkage is accounted for.

Useful to Know

• Bolt width and piece width interact in a way that isn’t always obvious: going up even slightly in bolt width (e.g. from 44” to 60”) can let more pieces fit per row, which can meaningfully reduce the total yardage needed for the same project.
• Buying a little more than this calculator’s raw result is common practice even beyond the waste margin — extra fabric is cheap insurance against a cutting mistake, and having leftover fabric for a future repair or matching accessory is rarely wasted.
• This calculator pairs naturally with the Yarn Amount Calculator for a related craft-material estimate, or the Picture Frame Mat Calculator when the finished pieces need mounting or framing.