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Calculator

Centrifuge RPM ↔ RCF

Protocols give speed in ×g, your centrifuge shows RPM, or the other way round. Enter the speed and the rotor radius to convert.

I have
RPM
mm

From the centre of the rotor to the bottom of the tube. Most rotors have it printed on the lid or in the manual.

Decimals and rounding

Far left picks a sensible number of decimal places for each value.

How it works

RCF = 1.118 × radius (mm) × (RPM ÷ 1000)², and the same formula solved for RPM the other way round. RCF is the relative centrifugal force in multiples of gravity, often written as ×g.

The same RPM gives a higher RCF on a larger rotor. That is why protocols should give ×g, and why this calculator needs the radius.