Centrifugal Force Calculator
Calculate centrifugal (centripetal) force for rotating objects.
Enter mass, velocity, and radius to find the outward force in Newtons and other units.
In circular motion, an object experiences an apparent “outward” force — the centrifugal force. In physics, the real force acting is the centripetal force, which acts inward toward the center of rotation and prevents the object from flying outward. These two concepts are different perspectives of the same phenomenon.
The Formula
For an object moving in a circle:
F = m × v² / r
Or equivalently using angular velocity (ω in radians per second):
F = m × ω² × r
Where:
- F = centripetal/centrifugal force (Newtons, N)
- m = mass of the object (kilograms, kg)
- v = tangential velocity (meters per second, m/s)
- r = radius of the circular path (meters, m)
- ω = angular velocity (radians per second, rad/s)
Converting RPM to Angular Velocity
If you know the rotational speed in RPM (revolutions per minute): ω = RPM × 2π / 60
Practical Examples
A 1 kg object on a 0.5 m string spinning at 2 m/s: F = 1 × (2)² / 0.5 = 1 × 4 / 0.5 = 8 N
A car (1,500 kg) taking a turn at 20 m/s (72 km/h) with a curve radius of 50 m: F = 1500 × (20)² / 50 = 1500 × 400 / 50 = 12,000 N
This force must be provided by friction between tires and road. If friction is insufficient, the car slides outward.
Applications
- Washing machine spin cycles
- Centrifuge machines (medicine, chemistry)
- Rollercoasters and banked road curves
- Satellite orbits (centripetal = gravity)
- Industrial equipment and grinding wheels
- Blood plasma separation
Units
1 Newton (N) = 1 kg·m/s² 1 lbf (pound-force) = 4.448 N