Enter values to see results
—
RPM
Enter values to see results
—
RPM
The RCF to RPM Converter helps you determine the centrifuge speed in revolutions per minute needed to achieve a specific g-force. When a protocol specifies centrifugation at a certain × g value, you need to convert that to RPM for your specific centrifuge and rotor combination.
Enter the desired RCF and your rotor radius, and this tool will calculate the exact RPM setting for your centrifuge.
Starting from the RCF formula, we solve for RPM:
RPM = √(RCF / (1.118 × 10⁻⁵ × r))
Where r is the rotor radius in centimeters. This is the algebraic rearrangement of the standard formula RCF = 1.118 × 10⁻⁵ × r × RPM².
Inputs
Results
To achieve 300 × g with a 15 cm rotor radius, set your centrifuge to approximately 1,337 RPM.
Inputs
Results
For a microcentrifuge with 8 cm radius, 16,000 × g requires about 13,374 RPM.
For most biological applications, being within 5-10% of the target RPM is sufficient. Centrifuges typically allow speed adjustments in increments of 100 RPM, so round to the nearest available setting. Critical applications like gradient separations may require more precision.
Use the maximum radius (r_max), which is the distance from the axis of rotation to the bottom of the tube. This gives the force at the bottom of the tube where the pellet forms. Some protocols specify r_min or r_avg; check the protocol details carefully.
If the required RPM exceeds your centrifuge maximum, you can increase the centrifugation time to partially compensate. Alternatively, use a different rotor with a larger radius, which produces higher g-force at the same RPM. Consult the protocol authors for alternative conditions.
Roboculator Team
The Roboculator Team explains calculations, planning tools, and practical formulas in clear language for real-life situations.
How helpful was this calculator?
Be the first to rate!
