What is a Centrifuge Calculator?

A Centrifuge Calculator is an essential tool for laboratory researchers and scientists to convert between the rotational speed (RPM) and the actual force applied to a sample, known as Relative Centrifugal Force (RCF) or g-force. Since different centrifuges have different rotor sizes, simply knowing the RPM is not enough to replicate an experiment. The RCF takes the radius of the rotor into account, providing a standardized measurement of force.

How to Calculate RCF from RPM

The standard formula used in this calculator is: RCF = 1.118 × 10^-5 × r × RPM². In this equation, 'r' represents the rotational radius in millimeters (mm). Using our online tool, you don't need to perform these complex calculations manually. Simply input the radius and the speed, and the tool will provide the precise g-force.

Why the Rotor Radius Matters

The radius is the distance from the center of the centrifuge spindle to the bottom of the centrifuge tube. Even if two centrifuges are running at the same RPM, the one with a larger rotor will exert a significantly higher RCF on the samples. Always check your centrifuge manual to find the maximum or minimum radius for your specific rotor model to ensure accuracy in your protocols.

Frequently Asked Questions

Q: What is the difference between RPM and RCF?
A: RPM (Revolutions Per Minute) measures how fast the rotor is spinning. RCF (Relative Centrifugal Force) measures the actual force exerted on the contents, which depends on both speed and the size of the rotor.

Q: Can I convert RCF back to RPM?
A: Yes! Our calculator works both ways. If you know the required g-force for your protocol and your rotor's radius, you can calculate the exact RPM needed.

Q: Is there a standard unit for radius?
A: Most scientific formulas use millimeters (mm) for the radius. If your measurement is in centimeters, multiply it by 10 before entering it into the calculator.