Cut Length
37.5"
Cut Width
46.4"
Extra Length
+1.5"
Cotton typically shrinks 3–5%. Pre-wash and dry before cutting to avoid surprises in your finished project.
| Fabric | Length % | Width % | Range |
|---|---|---|---|
| Cotton | 4.0% | 3.0% | 3–5% |
| Linen | 5.0% | 4.0% | 3–10% |
| Wool | 7.0% | 5.0% | 5–10% |
| Polyester | 0.5% | 0.5% | 0–1% |
| Rayon/Viscose | 5.0% | 4.0% | 3–8% |
| Denim | 5.0% | 3.0% | 3–10% |
| Desired | Cut At | Extra |
|---|---|---|
| 12" | 12.5" | +0.5" |
| 24" | 25.0" | +1.0" |
| 36" | 37.5" | +1.5" |
| 45" | 46.9" | +1.9" |
| 60" | 62.5" | +2.5" |
Inputs
Result
This cotton swatch shrank 4.2% in length and 3.1% in width, which is typical for unwashed cotton. Total area lost is about 7.1%, meaning a 36×45" piece became 34.5×43.6" after the first wash.
Inputs
Result
To end up with 36×45 inches after washing cotton (4% length, 3% width shrinkage), cut at 37.5×46.4 inches. That extra 1.5 inches in length and 1.4 inches in width compensates for shrinkage.
Inputs
Result
Wool’s higher 7% length shrinkage means cutting 4.5 inches extra on a 60-inch piece. Width shrinkage at 5% adds 2.4 inches. Pre-wash wool on a cold delicate cycle to get this shrinkage out before your project.
Cotton typically shrinks 3–5% in length and 2–4% in width after the first hot wash and dry cycle. The average is about 4% lengthwise. Pre-washed or "sanforized" cotton shrinks less than 1%. Always pre-wash cotton before cutting to avoid surprises in your finished project.
| Fabric | Length Shrink | Width Shrink | Typical Range |
|---|---|---|---|
| Cotton | 4% | 3% | 3–5% |
| Linen | 5% | 4% | 3–10% |
| Wool | 7% | 5% | 5–10% |
| Polyester | 0.5% | 0.5% | 0–1% |
| Rayon | 5% | 4% | 3–8% |
| Denim | 5% | 3% | 3–10% |
Measure a swatch before and after washing. Shrinkage % = (original − washed) / original × 100. For example, a 36-inch piece that measures 34.5 inches after washing has shrunk (36 − 34.5) / 36 × 100 = 4.17%. Always measure both length and width separately since they often shrink at different rates.
Divide your desired finished measurement by (1 − shrinkage/100). For example, if you want 36 inches finished and cotton shrinks 4%, cut at 36 / (1 − 0.04) = 36 / 0.96 = 37.5 inches. This ensures the fabric ends up at your target size after washing.
| Desired Size | At 3% Shrink | At 5% Shrink | At 7% Shrink |
|---|---|---|---|
| 12" | 12.4" | 12.6" | 12.9" |
| 36" | 37.1" | 37.9" | 38.7" |
| 45" | 46.4" | 47.4" | 48.4" |
| 60" | 61.9" | 63.2" | 64.5" |
Yes. Wool shrinks 5–10% on average (7% typical), compared to cotton’s 3–5%. Wool also felts when agitated in hot water, which causes irreversible shrinkage beyond simple relaxation. Always hand-wash or use a wool cycle with cold water and lay flat to dry.
Yes, always pre-wash natural fibers (cotton, linen, wool, rayon) before cutting. Most shrinkage happens in the first wash. If you skip pre-washing and the finished garment shrinks, seams pucker and the fit changes. Polyester and polyester blends (>50% poly) rarely need pre-washing.
Fabric typically shrinks more along the length (warp direction) than the width (weft direction). This is because warp yarns are under higher tension during weaving. Cotton shrinks about 4% in length but only 3% in width. Always measure and calculate shrinkage for both directions independently.
Read our guide
Read our guide
Read our guide
Discover tools for sewing, quilting, knitting, candle making, resin art, and more.
Last Updated: Mar 9, 2026
This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.