Coriolis Acceleration Calculator

About this calculator

An object moving across a rotating reference frame — like Earth's surface — experiences an apparent deflection that has nothing to do with any real force pushing it sideways; it's a consequence of the frame itself rotating underneath the object's path. Named after French engineer Gaspard-Gustave de Coriolis (1835), the acceleration is given by a = 2·Ω·v·sin(φ), where Ω is the frame's angular velocity, v is the object's velocity, and φ is latitude.

For Earth, Ω = 7.2921 × 10⁻⁵ rad/s, and the sin(φ) term means the effect is zero at the equator and strongest at the poles — which is why hurricanes and cyclones rotate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere, why ocean currents spiral (the Ekman spiral), and why long-range ballistics, artillery targeting and inertial navigation systems must all correct for it.