G Force Calculator — RCF to RPM

How to Convert RCF (G Force) to RPM and Vice Versa

Relative centrifugal force (RCF) is used to refer to the amount of force applied when using a centrifuge. To convert revolutions per minute (RPM) to relative centrifugal force (RCF), or g force, use the following formula: RCF = (RPM)2 × 1.118 × 10-5 × r. Relative centrifugal force is dependent on the speed of rotation in RPM and the distance of the particles from the center of rotation. When the speed of rotation is given in RPM and the distance (r) is expressed in centimeters, RCF can be calculated.

The calculator below will convert g force (RCF) from revolutions per minute (RPM) or vice versa to achieve more precise experimental and quality control results that require centrifugation. Find the g force by entering the RPM and centrifuge rotor radius. Or, calculate RPM given the g force (x g) and the centrifuge radius.

Calculate relative centrifugal force (RCF) to RPM and vice versa:

Revolutions per minute of rotor (RPM)  
Radius of rotor (cm)    
Relative Centrifugal Force (RCF) or g force  
   

RCF = 1.12 x Radius x (RPM/1,000)2

What is Centrifugation?

Centrifugation is a way to increase the magnitude of the gravitational field so that particles in suspension experience a radial centrifugal force that moves them away from the axis of rotation.

What is Relative Centrifugal Force?

The relative centrifugal force (RCF) or the g force is the radial force generated by the spinning rotor as expressed relative to the earth's gravitational force. The g force acting on particles is exponential to the speed of rotation defined as revolutions per minute (RPM).

Doubling the speed of rotation increases the centrifugal force by a factor of four. The centrifugal force also increases with the distance from the axis of rotation. These two parameters are of considerable significance when selecting the appropriate centrifuge.

Relative Centrifugal Force (RCF) Formula

Using the G Force Formula

RCF or g force is dependent on the speed of rotation in RPM and the distance of the particles from the center of rotation. When the speed of rotation is given in RPM and the distance (r) is expressed in centimeters, RCF can be calculated by using the following formula.

G Force Formula

g Force (RCF) = (RPM)2 × 1.118 × 10-5 × r

When the RPM is unknown and you are given a g force and radius (r), you can calculate RPM using the following formula:

RPM Formula

RPM = √[RCF/(r × 1.118)] × 1 × 105

RCF (g force) = relative centrifugal force

r = rotational radius (cm)
 

RPM Converted to G Force Chart (PDF)