CentriCraft: RCF/RPM Calc

CentriCraft converts between rotor speed and relative centrifugal force for lab researchers, students and technicians working at the centrifuge.

• Turn RPM into RCF (× g), or find the RPM needed to reach a target g-force
• Enter the rotor radius in centimeters, millimeters or inches
• Start from 19 fixed-angle and swing-bucket rotor presets for common centrifuge models, with their published maximum speeds
• Type a custom radius from your own rotor's spec sheet
• Save your own rotors with r_max, r_min, r_av, tube angle and maximum speed; get a warning when a result goes past the rotor’s rating
• Move a run to another rotor: the same g-force at the new speed, plus k factors and the adjusted pelleting time
• Plan multi-step protocols with force, time and temperature; every speed is worked out for your rotor
• See acceleration in m/s² and tip speed with each result; copy or share any result
• Out-of-range values and unreachable speeds are flagged before you spin
• Every result is logged in history; star the ones you reuse
• Show results with 0 to 3 decimal places

Calculations use the standard formula RCF = 1.118 × 10⁻⁵ × r(cm) × RPM².
The k factor uses k = 2.533 × 10¹¹ × ln(r_max/r_min) / RPM².

Results are calculated estimates. Verify speeds and forces against your instrument’s manual and your lab’s protocol before laboratory use.