Enter your object's mass, velocity, angular velocity, latitude, and angle to the rotation axis into the Coriolis Effect Calculator to compute the Coriolis force, Coriolis acceleration, and deflection distance acting on a moving body in a rotating reference frame. Choose your hemisphere to see which direction the deflection occurs.
Coriolis Force
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Coriolis Acceleration
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Deflection Distance
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Effective ω at Latitude
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Deflection Direction
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The Coriolis effect is an apparent deflection of moving objects caused by Earth's rotation. An observer in a rotating reference frame (like Earth's surface) sees moving objects curve from their expected straight-line path. In the northern hemisphere, deflection is to the right; in the southern hemisphere, it is to the left.
The Coriolis force magnitude is calculated as F = 2 × m × v × ω × sin(α), where m is the object's mass, v is its velocity, ω is the angular velocity of the rotating frame, and α is the angle between the velocity vector and the rotation axis. For motion on Earth's surface at a given latitude, the effective vertical component of ω is ω × sin(latitude).
The Coriolis effect is the key driver behind large-scale atmospheric and oceanic patterns. It causes winds to spiral around high- and low-pressure systems (forming cyclones and anticyclones), and deflects ocean currents into massive gyres. Without it, air and water would flow directly from high to low pressure rather than rotating.
The Coriolis effect becomes significant for objects traveling over large distances or long time periods — such as missiles, aircraft, ocean currents, and wind patterns. For everyday short-range activities like flushing a toilet or throwing a ball, the Coriolis force is many orders of magnitude too small to have any observable effect.
Earth completes one full rotation (2π radians) approximately every 24 hours, giving an angular velocity ω ≈ 0.0000727 rad/s. This is the default value pre-filled in the calculator. For other rotating systems (e.g. a turntable or centrifuge), you can enter a custom angular velocity.
The Coriolis force is strongest at the poles (latitude 90°) and zero at the equator (latitude 0°). This is because the effective vertical component of Earth's angular velocity is ω × sin(latitude). At the equator, the rotation axis lies horizontal, so there is no vertical component to deflect horizontal motion.
Aircraft and long-range missiles traveling for extended periods must account for Coriolis deflection in their navigation. A missile fired northward from the equator will appear to deflect eastward in the northern hemisphere. Autopilot systems and inertial navigation units incorporate Coriolis corrections to maintain accuracy over long distances.
No — the Coriolis force is a 'fictitious' or 'pseudo' force. It only appears when analyzing motion from within a rotating reference frame. An observer in an inertial (non-rotating) frame would see the object move in a straight line; it is the frame itself that is rotating beneath the object, creating the apparent deflection.