A TEU or a Twenty-Foot Equivalent Unit is a 20-feet long shipping container that is widely used as the benchmark for calculations in shipping & logistics.TEU ratio is calculated by simply dividing the length in feet of the container by Twenty. For example, a (20ft x 8ft x 8ft) container will be 1 TEU. A (40ft x 8ft x 8ft) container will be 2 TEU (48ft x 8ft x 8ft) the container will be 2.4 TEU. TEUs are the standard unit of measuring the carrier capacity. Since it's the minimum unit, TEUs can be converted to other container dimensions.