In a rotating frame – a car on a curve, a spin dryer, a carousel – objects seem to be pushed outward. This centrifugal force is an inertial force: from outside it is just the object’s tendency to keep moving in a straight line. It has the same size as the centripetal force.
How to use the Centrifugal Force Calculator
- Mass m
- Radius r
- Speed given as
- Tangential velocity v
- Angular velocity ω
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Enter the mass and radius, then either the speed or the angular velocity.
Inputs explained
| Field | What to enter |
|---|---|
| Mass m | Units: kg, g, mg, t, lb, oz |
| Radius r | Units: m, cm, mm, km, in, ft … |
| Speed given as | Choose one: Tangential velocity v, Angular velocity ω |
| Tangential velocity v | Units: m/s, km/h, mph, ft/s, knots, km/s |
| Angular velocity ω | Units: rpm, rad/s, Hz (rev/s) |
What each result means
- Centrifugal force = [Mass m]×[w]^2×[Radius r]
- Relative to gravity = [w]^2×[Radius r]÷9.80665
- Tangential speed = [w]×[Radius r]
Example values
How the main result changes when Mass m changes and everything else stays at the example values above:
| Mass m (kg) | Centrifugal force (N) |
|---|---|
| 0.5 | 1,973.9209 |
| 0.75 | 2,960.8813 |
| 1 | 3,947.8418 |
| 1.25 | 4,934.8022 |
| 1.5 | 5,921.7626 |
| 2 | 7,895.6835 |
Formula
F = m·v²/r = m·ω²·r
Worked example
Inputs — Mass m: 1 kg; Radius r: 0.25 m; Speed given as: Angular velocity ω; Angular velocity ω: 1,200 rpm.
Results — Centrifugal force = 3,947.8418 N; Relative to gravity = 402.57 g; Tangential speed = 31.4159 m/s.
Key terms
- Inertial force
- An apparent force in an accelerating frame.
Frequently asked questions
Is centrifugal force real?
It is a fictitious (inertial) force that appears only in a rotating frame.
How does a spin dryer use it?
Water is flung outward through the holes in the drum.
What is the difference from centripetal force?
Centripetal force is the real inward force; centrifugal is the apparent outward force.
Why does force grow so fast with rpm?
It depends on ω², so doubling the speed quadruples the force.