Fabric Shrinkage Calculator
Calculates how many extra yards of fabric to purchase to account for shrinkage when pre-washing before sewing. Essential when working with natural fibers like cotton or linen that shrink significantly.
Last updated: September 2026
Formula below · 1 source (Wikipedia) · Updated Sep 2026
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About this calculator
Fabric shrinks when washed and dried, so you must buy enough that what is left after pre-washing still covers your project. The base shrinkage rate depends on the fiber (polyester about 2%, cotton blends 3%, 100% cotton 5%, linen 8%, wool 10%), and warmer washing and hotter drying increase it: the wash setting multiplies the rate by 1.0 (cold), 1.2 (warm) or 1.5 (hot) and the dryer setting by 1.0 (air dry), 1.3 (low heat) or 1.6 (high heat). Expected shrinkage s = fiber rate × wash factor × dryer factor. To end up with the required length after shrinking, buy required ÷ (1 − s), rounded up to the next 1/8 yard because shops cut in eighths: Fabric to Buy = ⌈required ÷ (1 − s) × 8⌉ / 8. Shrinkage along the length and across the width can differ; this estimate applies to the length.
How to use
Say your project needs 3 yards of 100% cotton (5%), you plan to wash in hot water (×1.5) and dry on high heat (×1.6). Step 1: expected shrinkage = 0.05 × 1.5 × 1.6 = 0.12 (12%). Step 2: fabric to buy = 3 ÷ (1 − 0.12) = 3.41 yards. Step 3: round up to the next 1/8 yard: ⌈3.41 × 8⌉ / 8 = 28 / 8 = 3.5 yards. Buy 3½ yards. Washed cold and air-dried, the same cotton needs 3 ÷ 0.95 = 3.16, so 3¼ yards.
Frequently asked questions
How much does cotton fabric typically shrink when washed?
Cotton typically shrinks between 3% and 7% depending on the weave and finish. Tightly woven quilting cotton tends toward the lower end, while loosely woven or unfinished cotton can shrink 7% or more. Washing in hot water and drying on high heat compounds the effect. Pre-washing before cutting is strongly recommended for cotton garments and quilts to avoid distortion after the finished item is laundered.
Why is fabric shrinkage calculated to the nearest one-eighth yard?
Fabric stores and online retailers cut and sell fabric in increments of one-eighth yard (4.5 inches) because bolts are measured on rulers divided into eighths. Rounding your shrinkage calculation to the nearest ⅛ yard ensures you order an amount the store can actually cut for you. Ceiling-rounding (always rounding up) means you never end up short of pre-washed fabric for your project.
Does dryer heat cause more shrinkage than washing temperature?
Both factors contribute to shrinkage, but dryer heat — especially sustained high heat — is generally the larger driver for most natural fibers. Washing agitation loosens fiber tension, but it's the heat of drying that causes fibers to contract and set in their shrunken state. Using a low-heat or air-dry setting can significantly reduce total shrinkage, sometimes cutting it by half compared to high-heat drying. If you always air-dry finished garments, you may be able to use a lower shrinkage estimate.