Convert centrifuge speed between RPM and relative centrifugal force (×g) using rotor radius.
Calculate now ↓RCF = 1.118×10⁻⁵ × r × RPM²Convert centrifuge speed using the actual rotor radius instead of relying on RPM alone.
Use the radius from the center of rotation to the sample position specified for your rotor geometry.
Translate between RPM and ×g for a specified rotor radius.
Tossora Lab keeps units, intermediate values, and practical preparation checks visible so a mathematically correct answer is easier to translate into an experimental workflow.
Research use only. Verify critical calculations, reagent specifications, route or instrument limits, and procedures against your approved protocol and institutional requirements.
Use this RCF to RPM calculator when a protocol specifies relative centrifugal force but the instrument displays RPM, or when you need to translate an RPM setting into ×g. Rotor radius remains part of the calculation because two rotors at the same RPM can generate different centrifugal force.
Open the calculatorWhat force is generated with an 8.5 cm rotor radius?
The calculated force is approximately 13,684 ×g.
Interpretation: Use the radius definition appropriate to the protocol and rotor documentation; maximum, minimum and average radius are not interchangeable.
What RPM is required with a 10 cm radius?
The required speed is approximately 9,457 RPM.
Interpretation: Confirm the rotor and instrument are rated for the selected speed and that the protocol’s time and temperature conditions are also matched.
RPM describes rotational speed, not the force experienced by the sample.
Convert using the actual rotor radius or match the protocol’s stated ×g value.
Entering the full rotor diameter doubles the radius term and produces an incorrect force.
Use the distance in centimeters from the axis of rotation to the specified sample position.
Swinging-bucket and fixed-angle rotors can have different relevant radii, and hardware has rated speed limits.
Check the instrument and rotor manual before applying the calculated setting.
Copy a methods-ready sentence or preparation checklist, then adapt it to your actual protocol, instrument and acceptance criteria.
Samples were centrifuged at the stated relative centrifugal force, duration and temperature using the specified rotor; RPM was calculated from the applicable rotor radius when required.
Record centrifuge, rotor model, radius definition, set RPM or RCF, calculated counterpart, duration, temperature and brake setting.
No. RPM is rotational speed, while RCF is the acceleration relative to gravity and depends on both RPM and rotor radius.
Use the radius definition specified by the protocol or equipment documentation. If it is unclear, verify whether the method expects maximum, minimum or average radius.
RCF increases linearly with radius and with the square of RPM, so rotor geometry changes the force at a given speed.
No. Confirm rotor compatibility, rated maximum speed, balance, temperature, time and brake settings in the equipment instructions and protocol.
The implementation applies RCF = 1.118 × 10⁻⁵ × radius(cm) × RPM² and its algebraic inverse while keeping rotor radius visible.
Use the radius definition required by the protocol or rotor manual and confirm rotor compatibility, rated speed, balance, duration, temperature and brake settings before a run.
SI prefixes, symbols and base-unit normalization.
RCF = 1.118 × 10⁻⁵ × radius(cm) × RPM².
Scope: Exact arithmetic reference; the applicable rotor radius and safe operating limits require equipment review.
12 August 2026 · Internal implementation review
Bidirectional RPM and RCF conversion review complete. Formula behavior, unit handling, limitations and linked references were checked internally.
Independent reviewer: Not yet published. A name, relevant qualification, date and exact scope will appear here only after a real review is completed.
Source-informed and internally checked; independent scientific or regulatory validation is not claimed. Research use only.