13 1/2" tall, 17" long, across bottom for width is 8 ". All the measurements are approximate. 1) I'm using my son's ruler instead of tape measure. 2) there is extra material for expansion so it's difficult to measure seam to seam. Over sized comes in with the expansion capacity of the three main pockets. The few times we did use it. It easily held diapers, wipes, bottles, formula, change of clothes, etc for triplets.