Zerdly

Centrifugal Force Calculator

Calculate the centrifugal (radial) force acting on a mass rotating at a fixed radius, from its mass, radius and rotational speed. Useful for sizing rotor components, checking clamping forces and understanding why spinning parts want to fly apart.

100% FreeRuns in your browserIntermediate
How to use this calculator

Enter Values

Enter your values and press Calculate to see results.

How to use this calculator

  1. Enter the rotating mass m in kilograms.
  2. Enter the radius r in metres from the axis to the mass centre.
  3. Enter the rotational speed N in rpm, then read the centrifugal force plus the angular velocity and tangential rim speed.

How it works

Angular velocity is omega = 2 x pi x N / 60. The centrifugal force is F = m x omega^2 x r, and the tangential (rim) speed is v = omega x r. Force grows with the square of speed and linearly with radius and mass, so large-radius, high-speed rotors develop very large forces.

Worked example

Worked example. A 2 kg mass at a radius of 0.5 m spinning at 300 rpm gives omega = 2 x pi x 300 / 60 = 31.42 rad/s, so F = 2 x 31.42^2 x 0.5 = 986.96 N, with a rim speed of 31.42 x 0.5 = 15.71 m/s.

Common mistakes

  • Entering radius in millimetres instead of metres — this tool expects metres.
  • Using speed in rad/s or Hz rather than rpm; the tool converts rpm internally.
  • Forgetting that centrifugal force scales with the square of speed, so a modest overspeed hugely increases the load.

Frequently asked questions

Is centrifugal force a real force?

In the rotating frame it appears as an outward force, but physically it is the centripetal force required to keep the mass on its circular path. The magnitude m x omega^2 x r is the same either way.

What limits how fast a rotor can spin?

Beyond this force, rotor balance quality, bearing capacity and the material's tensile strength (burst speed) set the safe maximum — always design to the relevant standard.

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Tip: Enter any known values to calculate the remaining results.

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