How this calculator works
RCF compares radial acceleration with standard Earth gravity. Radius is measured from the rotation axis to the sample position; use the same minimum, mean or maximum radius specified by your protocol. The calculation uses standard gravity without rounding the common conversion constant. It estimates acceleration and does not select a sample-specific centrifugation time.
Formula
RCF = (2 pi rpm/60)² r/9.80665, with r in metres. With centimetres, the rounded coefficient is 1.118e-5.
Worked example
At a 10 cm radius, 1000 rpm produces about 111.824 times g. Doubling speed to 2000 rpm at the same radius gives about 447.298 times g.
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Frequently asked questions
Are rpm and RCF interchangeable?
No. RCF also depends on radius, so identical rpm settings on different rotors may give different accelerations.
Which radius should I enter?
Use the sample radius specified by the protocol or rotor manufacturer, often the maximum radius to the tube bottom.
Why is the answer slightly different from a printed table?
Tables often round the coefficient to 1.118e-5 and round their displayed RCF values.