TaskJunction

Cutting Speed and RPM Calculator

Spindle RPM and table feed from cutting speed, tool diameter, and chip load.

Inputs

Results

Spindle RPM
—
Table Feed
—
Actual Cutting Speed
—

Formula

  • n = (Vc × 1000) / (π × D)
  • Vf = fz × Z × n
  • Vc in m/min, D in mm, fz in mm/tooth, Z = number of teeth

About this calculator

Part of our Machining & CNC Calculators collection. Cutting speed, feeds, RPM, cycle time, and tap drill charts.

How it works

Spindle speed equals cutting speed times 1000 divided by pi times tool diameter. Table feed equals RPM times feed per tooth times number of teeth. Start with your material cutting speed and adjust for machine limits.

Enter your values in the inputs above and click CALCULATE. Results appear on the right without a page reload. No login and no server upload.

Worked example

120 m/min cutting speed, 25 mm end mill, 0.10 mm/tooth, 4 flutes.

  1. n = 120 × 1000 / (π × 25) = 1,528 → rounded 1,528 RPM
  2. Vf = 0.10 × 4 × 1,528 = 611 mm/min
  3. Actual Vc = π × 25 × 1,528 / 1000 = 120.0 m/min

Result: 1,528 RPM, 611 mm/min feed, actual cutting speed 120 m/min.

When to use

  • Converting recommended cutting speed to spindle RPM
  • Computing table feed from chip load per tooth
  • General milling or turning speed setup

Limitations

  • Does not check machine power, rigidity, or tool holder limits
  • Chip load should come from tool manufacturer data for your material
  • Rounded RPM slightly changes actual cutting speed

FAQ

What is cutting speed Vc?
The speed at which the tool edge moves through the workpiece surface, in m/min. Material and tool catalogs list starting values.
Why round RPM?
CNC machines and manual dials use integer RPM. Rounding matches what you can actually dial in on the machine.
How is feed rate different from feed per tooth?
Feed per tooth (fz) is chip load per cutting edge. Table feed Vf = fz × number of teeth × RPM.

Privacy and accuracy

Every calculation runs locally in your browser. Your design data never leaves your device. Results are intended for preliminary engineering work. Always verify critical designs with qualified review and applicable standards before production use.

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