Free AI-Assisted

RCF to RPM Calculator

Convert RPM and ×g with rotor lookup, tri-radius output, and protocol transfer—no account. Built-in AI agent assistant support.

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Key facts

Key facts about RCF to RPM Calculator
FactValue
ModesConverter (RPM ↔ RCF), Protocol Transfer, Batch CSV, History
Rotor presets10 models — Beckman, Eppendorf, Thermo/Sorvall; searchable by model or manufacturer
Manual fallbackEnter rmin, ravg, rmax in mm or cm when rotor is not listed
OutputsTri-radius ×g or RPM; tube force-gradient diagram; methods-section text
Protocol transferSource RPM + rotor → equivalent target RPM at matched rmax ×g
WarningsMax-RPM exceedance; RPM > 150,000; fixed-angle vs swing-bucket mismatch
HistoryLast 10 calculations stored in browser
Runs in browserYes — no install
Account requiredNo
Data uploadLocal only — batch CSV pasted in browser

What it does

Copying RPM from a published protocol without matching rotor geometry can double or halve the g-force on your sample—a silent error that ruins pellets or lyses cells. The RCF to RPM Calculator converts centrifuge speed bidirectionally using rotor radius, shows rmin, ravg, and rmax ×g in one view, and flags over-speed before you spin.

Search Rotor search for a preset (Beckman, Eppendorf, or Thermo/Sorvall models) or choose Enter radius manually and fill rmin, ravg, and rmax in mm or cm. Toggle RPM → RCF or RCF → RPM, enter speed, and optional Duration (min) and Temp (°C) for methods text. Results update live: tri-radius ×g or RPM values, a tube force-gradient diagram, and Copy rmax ×g or Copy rmax RPM. Use Protocol Transfer to map source RPM on one rotor to the matching RPM on another. Paste multi-step protocols in Batch as CSV and Export CSV when done.

Why researchers use it

  • Avoid copying RPM without rotor geometry correction
  • See rmin, ravg, and rmax g-force in one view
  • Catch over-speed before running a rotor
  • Transfer published spin steps to your centrifuge
  • Paste methods-ready ×g text into manuscripts
  • Convert multi-step protocols in one batch paste

Best for

  • Converting protocol RPM to ×g for papers and SOPs
  • Pelleting cells or bacteria at matched force
  • Density gradient centrifugation planning
  • Moving methods between shared centrifuges
  • Multi-step spin protocols in batch CSV
  • Core facility rotor cross-reference

When to use this vs alternatives

Choose this tool when you need searchable rotor presets, tri-radius output, protocol transfer, and copy-ready methods text in one browser session. Use the Eppendorf online calculator when you only run Eppendorf rotors and want vendor-specific adapter guidance. ConductScience fits quick radius-only math without a rotor database. ScienceGateway still works for legacy Beckman/Sorvall lookup but lacks tri-radius display, safety warnings, and methods output. For solution concentration before a spin step, use the Molarity Solution Calculator instead.

What makes it different

Most converters return one ×g value from a manually entered radius and never check rotor speed limits or help you move a protocol to a different centrifuge. ScienceGateway covers a few legacy brands but lacks tri-radius display, safety warnings, and methods text. Eppendorf's calculator is accurate only for its own rotors. ConductScience offers batch CSV and methods output but requires manual radius entry and shows no max-RPM check.

This browser calculator combines searchable rotor presets across three manufacturers, simultaneous rmin–rmax output with a force-gradient diagram, max-RPM alerts, protocol transfer between rotors, batch CSV conversion, and copy-ready methods text—in one workspace with live results, no install.

How to get started

  1. Open the workspace and stay on the Converter tab.
  2. Toggle RPM → RCF or RCF → RPM for your conversion direction.
  3. Search Rotor search for your model, or click Enter radius manually and fill rmin, ravg, rmax.
  4. Enter RPM or RCF (×g); add Duration (min) and Temp (°C) if you need methods text.
  5. Review tri-radius results, the tube diagram, and any warnings; click Copy rmax ×g or edit the methods bar and copy.
  6. For a different centrifuge, open Protocol Transfer, set source and target rotors, and enter Source RPM. For multiple steps, paste CSV on Batch and click Export CSV.

Frequently asked questions

How do I convert RPM to RCF (×g)?
Select RPM → RCF, search for your rotor or enter rmin, ravg, and rmax in millimeters or centimeters, then type your RPM. The calculator applies RCF = 1.118×10⁻⁶ × r(mm) × RPM² at each radius and shows rmin, ravg, and rmax ×g simultaneously. Results update as you type—no submit button. For pelleting protocols, use the rmax value; the tube diagram shows force from top to bottom of the tube.
Which radius should I use — rmin, ravg, or rmax?
rmax (maximum radius, bottom of the tube) is standard for pelleting and most published ×g values. rmin and ravg matter for density gradients where force varies along the tube length. This calculator shows all three at once so you do not need three separate runs. Field labels note that rmax is for pelleting; the force-gradient diagram visualizes the span from rmin to rmax.
Why does the same RPM give different g-force on different rotors?
RCF depends on rotor radius as well as RPM. A larger rotor at 10,000 RPM applies higher ×g than a smaller rotor at the same speed. Copying RPM from a protocol without converting for your rotor geometry is the most common centrifuge transfer error. Use Protocol Transfer to enter the source rotor and RPM, select your target rotor, and get the equivalent target RPM matched at rmax ×g.
What if my rotor is not in the database?
Click Enter radius manually in Rotor search and type rmin, ravg, and rmax from your rotor manual or centrifuge label. Optionally enter Max RPM for a safety warning when your entered speed exceeds the rated limit. The database currently includes 10 presets across Beckman, Eppendorf, and Thermo/Sorvall models; manual entry works for any rotor with known radii.
What does the max-RPM warning mean?
When a selected rotor preset includes a rated maximum speed, or you enter Max RPM manually, the tool flags speeds above that limit with a non-blocking warning: "Exceeds rated max of X RPM." The conversion still displays so you can evaluate the value, but you should verify against your rotor manual before spinning. Speeds above 150,000 RPM also trigger a bench-range verification notice.

Client source code & registry

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Last updated . Pepkio builds free lab calculators alongside bioinformatics CRO services.