What is the Coriolis force?

The Coriolis force is an apparent (pseudo) force that acts on objects moving in a rotating reference frame, such as Earth. It deflects moving air and water to the right in the Northern Hemisphere and to the left in the Southern Hemisphere, influencing weather systems and ocean currents.

What is the Coriolis force formula?

F = 2mΩv sin(φ), where m is the mass in kg, Ω is Earth's angular velocity (7.2921 × 10⁻⁵ rad/s), v is the object's speed in m/s, and φ is the latitude in degrees. The result is in Newtons.

Why is the Coriolis force zero at the equator?

At the equator, φ = 0°, so sin(0°) = 0, making the force zero. The Coriolis effect is strongest at the poles (φ = ±90°) where sin(φ) = 1, and zero at the equator.

What is the Coriolis parameter f?

The Coriolis parameter f = 2Ω sin(φ) is a widely used quantity in meteorology and oceanography. It represents the vertical component of Earth's rotation vector at a given latitude and has units of s⁻¹.

Does the Coriolis force affect water draining in a sink?

No — household drains are far too small for the Coriolis force to dominate. The force is roughly 10⁻⁵ times gravity for typical water speeds, so basin geometry and residual motion have a much larger effect. Coriolis influence becomes significant only at scales of tens to hundreds of kilometers.

What units does this calculator use?

Mass in kilograms (kg), speed in meters per second (m/s), latitude in degrees (°), and force in Newtons (N). Convert your values to SI before entering them.

Coriolis Force Calculator

Compute the Coriolis force on a moving object at any latitude using F = 2m × v × Ω × sin(φ).

Inputs

Enter mass, speed, and latitude to compute the Coriolis force.

Mass (m)

Speed (v)

m/s

Latitude (φ)

° (−90 to 90)

Quick latitudes:

Result

Enter values and click Calculate.

Formula Reference

Coriolis Force

F = 2mΩv sin(φ)

Earth's Angular Velocity

Ω = 7.2921 × 10⁻⁵ rad/s

Coriolis Parameter

f = 2Ω sin(φ)

Ω is Earth's sidereal rotation rate. The force is zero at the equator (sin 0° = 0) and maximum at the poles (sin 90° = 1). The direction of deflection reverses across hemispheres — rightward in the Northern Hemisphere, leftward in the Southern.

Summary

The Coriolis Force Calculator applies the formula F = 2mΩv sin(φ) to find the apparent deflecting force on a moving object caused by Earth's rotation. Enter the object's mass, its speed, and the geographic latitude to get the Coriolis force magnitude and the Coriolis parameter (f = 2Ω sin φ) used in meteorology and oceanography.

How it works

Enter the mass of the moving object in kilograms.
Enter the object's speed in meters per second.
Enter the geographic latitude in degrees (0° = equator, 90° = pole).
Click Calculate to apply F = 2mΩv sin(φ) using Earth's angular velocity Ω = 7.2921 × 10⁻⁵ rad/s.
The result shows the Coriolis force in Newtons, the Coriolis parameter f, and a step-by-step breakdown.

Use cases

Meteorology coursework on how Earth's rotation deflects wind patterns.
Oceanography problems calculating current deflection at different latitudes.
Physics or geophysics homework involving apparent forces in rotating frames.
Ballistics and long-range projectile analysis where Coriolis deflection matters.
Understanding why cyclones rotate counterclockwise in the Northern Hemisphere.
Estimating Coriolis acceleration for a vehicle traveling across a large continent.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu