Levi's Shrink-to-Fit jeans shrink about 1 to 3 inches in the waist depending on size, and the inseam shrinks 3 to 4 inches. Larger sizes shrink more. Shrinkage in other Levi's jeans is negligible.
Levi's recommends that individuals with waist sizes up to 36 inches allow an extra inch in the waist, whereas those with waists between 38 and 48 inches should allow 2 extra inches. For a 50-inch waist size or larger, allow an extra 3 inches. For inseams up to 34 inches, increase the size by 3 inches. For inseams of 36 inches and higher, increase the size by 4 inches.
Levi's Shrink-to-Fit jeans are constructed of the same type of raw denim manufacturers used prior to the 1960s. Wearers purchase the jeans in a too-large size, wear the jeans for weeks or months without washing to break them in, and finally wash them only after the jeans have conformed to their body shapes. Washing and drying the jeans set the size and shape. However, raw denim may continue to shrink slightly during subsequent washes.