**A basic equation of physics,** for those out there building their own centrifuges:

### What are RPM, RCF, and g force and how do I convert between them?

The magnitude of the radial force generated in a centrifuge is expressed relative to the earth’s gravitational force (g force) and known as the RCF (relative centrifugal field). RCF values are denoted by a numerical number in “g” (ex. 1,000 x g). It is dependent on the speed of the rotor in revolutions per minute (RPM) and the radius of rotation. Most centrifuges are set to display RPM but have the option to change the readout to RCF.

**To convert between the two by hand, use the following equation:**

RCF = 11.18 (rcm) (rpm/1000)^2

Where **rcm = the radius** of the rotor in centimeters.