Centrifugation RCF/RPM Calculator

Centrifugation is a process that uses centrifugal force to separate components of different densities within a liquid. It's commonly used in laboratories to separate cells, proteins, DNA, and other biological materials.

RCF is the centrifugal force expressed as multiples of Earth's gravitational force (g). It provides a standardized way to describe centrifuge conditions regardless of the specific centrifuge model or rotor used.

RCF (Relative Centrifugal Force) is the force applied to samples as a multiple of gravity, while RPM (Revolutions Per Minute) is the rotational speed. RCF is the preferred unit because it accounts for rotor radius and provides consistent results across different centrifuges.

RPM measures rotational speed, while RCF measures the actual force applied to samples. The same RPM can produce different RCF values depending on rotor radius. Using RCF ensures reproducible results across different centrifuges and protocols.

The rotor radius is typically listed in your centrifuge manual or on the rotor itself. It's measured from the center of rotation to the center of the sample tube. Different rotors have different radii, so always check your specific rotor specifications.

Rotor radius directly affects the centrifugal force applied to samples. A larger radius generates more force at the same RPM. This is why protocols should specify RCF rather than RPM for reproducible results.

The formula is: RCF = (RPM)² × 1.118 × 10⁻⁵ × r, where r is the rotor radius in centimeters. This formula accounts for both rotational speed and the distance from the center of rotation.

Yes, this calculator works for any centrifuge as long as you know the rotor radius. The physics of centrifugal force is the same whether you're using a microcentrifuge, benchtop centrifuge, or high-speed ultracentrifuge.