Rated speed is the speed at which the elevator car is designed to travel under rated load conditions, expressed in metres per second (m/s). It is a fundamental design parameter that determines the motor power, governor trip speeds, buffer type, shaft overhead and pit depth, and overall system performance. Common rated speeds are 0.63 m/s and 1.0 m/s for residential elevators, 1.0–1.6 m/s for standard commercial elevators, and 2.5–10 m/s for high-speed or high-rise elevator installations.