Mid Back Ergonomic Task Chair with Adjustable Arms Seat Size: 20''W x 17.5''D Back Size: 17.5''W x 16.5''H Seat Height: 17'' - 21.5''H Arm Height: 8.5''-11.5''H From Seat; 25.5''-32.5''H From Floor Overall Dimensions: 25''W x 22.5''D x 33'' - 37.5''H