How do you convert RPM to RCF?

RCF = 1.118 × 10⁻⁵ × r × RPM², where r is the rotor radius in centimeters. Enter your rotor radius and speed and the calculator returns the relative centrifugal force in ×g.

Should I use RPM or RCF to reproduce a protocol?

Always RCF (×g). RPM produces different forces on different rotors because force depends on radius. Two centrifuges at the same RPM apply different g-forces if their rotor radii differ — so a published protocol should be matched by RCF.

Where do I find my rotor radius?

It is on the rotor or centrifuge specification sheet, listed as the radius (r max) — the distance from the rotor axis to the bottom of the tube. Use r max for the force at the tube bottom.

RCF ⇄ RPM Calculator

Convert between rotor speed (RPM) and relative centrifugal force (RCF, ×g) using your rotor radius. Reproduce any centrifugation protocol correctly — by force, not speed.

Rotor radius (mm)

The distance from the rotor center to the tube bottom — on the rotor or centrifuge spec sheet.

Speed (RPM)

Relative Centrifugal Force

1,789 × g

Formula: RCF = 1.118 × 10⁻⁵ × r(cm) × RPM². Always convert protocols by RCF (×g), not RPM — RPM is rotor-dependent.

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Frequently asked

How do you convert RPM to RCF?: RCF = 1.118 × 10⁻⁵ × r × RPM², where r is the rotor radius in centimeters. Enter your rotor radius and speed and the calculator returns the relative centrifugal force in ×g.
Should I use RPM or RCF to reproduce a protocol?: Always RCF (×g). RPM produces different forces on different rotors because force depends on radius. Two centrifuges at the same RPM apply different g-forces if their rotor radii differ — so a published protocol should be matched by RCF.
Where do I find my rotor radius?: It is on the rotor or centrifuge specification sheet, listed as the radius (r max) — the distance from the rotor axis to the bottom of the tube. Use r max for the force at the tube bottom.

RCF ⇄ RPM Calculator

Frequently asked

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