The standard units for acceleration are “metres per second squared”, written as m/s2\text{m/s}^2m/s2 or \text{m·s}^{-2} in SI units.

Basic idea

  • Acceleration measures how quickly velocity changes with time, so its units come from “velocity ÷ time”.
  • Velocity has units of metres per second (\text{m/s}), and dividing by seconds again gives \text{m/s}^2.

Common acceleration units

  • SI (standard) unit : metres per second squared, \text{m/s}^2.
  • CGS unit: centimetres per second squared, \text{cm/s}^2.
  • “g” (acceleration due to gravity): about 9.8\text{ m/s}^2 at Earth’s surface; 1 g is used a lot in engineering and aviation.

Why “per second squared”?

  • Writing \text{m/s}^2 means “metres per second per second”: every second, the velocity changes by a certain number of metres per second.
  • The notation \text{m·s}^{-2} is just another mathematically equivalent way to write the same unit.

Information gathered from public forums or data available on the internet and portrayed here.