To find the right size for Shrink To Fit Jeans, there are three options. Go old school: buy true to size in the waist and two sizes up in length. Wear them in the tub, keep on to dry. If you plan on line drying: buy up to two sizes larger in length and waist. Machine wash on warm, air dry for a classic rigid feel. For purists who like their denim unwashed: no need to size up, just hang them outside in the sun from time to time.