Fabric Shrinkage Calculator
Calculate fabric shrinkage percentage accurately before and after washing. Learn shrinkage rates and pre-wash allowances for cotton, linen, wool, and rayon.
Measure and calculate fabric wash shrinkage percentage before cutting and sewing. Input pre-wash and post-wash swatch measurements to determine warp and weft shrinkage, check whether your fabric meets industry stability benchmarks, and discover proper pre-wash allowances.
Key Features & Calculations
- Length and width shrinkage calculations
- Detects fabric stretch if expansion occurs
- Textile stability evaluations against standard tolerances
- Pattern cutting compensation tips
- Fiber-specific reference guidelines (Cotton, Linen, Rayon, Wool)
Frequently Asked Questions
What is the formula for calculating fabric shrinkage?
The standard textile industry formula for shrinkage percentage is: Shrinkage % = ((Measurement Before Washing - Measurement After Washing) / Measurement Before Washing) × 100. For example, if a 10-inch test swatch measures 9.5 inches after washing: ((10 - 9.5) / 10) × 100 = 5% shrinkage.
What is a normal shrinkage percentage for fabrics?
Normal shrinkage ranges by fiber type: Pre-shrunk / Sanforized cottons: 1% to 3%; Standard 100% Cotton & Lawn: 3% to 5%; Pure Linen: 4% to 7%; Rayon / Viscose: 5% to 8%; Untreated Wool: 5% to 15% (can shrink dramatically if exposed to hot water and agitation); Synthetics (Polyester, Nylon): 0% to 1.5%.
Why should I pre-wash fabric before sewing?
Yarns undergo mechanical tension on the industrial loom during weaving. When exposed to warm water and agitation during washing, the fibers relax and contract to their natural equilibrium state. If you sew a garment before pre-washing, the finished piece will shrink along seams, distort armholes, and shorten hem lengths on the very first laundry cycle.