11-quart colander measures 15-3/4" outer diameter, 14-1/2" inner diameter, 6-5/8" high with base, 5-1/2" deep. 16-quart colander measures 17-1/2" outer diameter, 16-1/4" inner diameter, 7-1/4" high with base, 6-1/8" deep. Hefty heavy duty aluminum built to withstand repeated use throughout the day in commercial kitchens.