Spindle Speed Calculator

Calculate the optimal spindle speed (RPM) for your CNC machine based on cutting speed and tool diameter.

Cutting Parameters
Surface Feet per Minute - depends on material
Typical: 0.001-0.010 inches
Results

Enter cutting parameters and click Calculate to see results.

How to Use
  1. Select your material from the dropdown or enter a custom cutting speed
  2. Enter the diameter of your cutting tool
  3. Enter the number of flutes on your tool
  4. Enter the chip load per tooth (consult your tool manufacturer)
  5. Click Calculate to get the optimal spindle speed and feed rate
About Spindle Speed Calculator

This calculator helps you determine the optimal spindle speed (RPM) and feed rate for your CNC machine.

Formula:

RPM = (Cutting Speed × 12) ÷ (π × Tool Diameter)

Feed Rate = RPM × Number of Flutes × Chip Load per Tooth

Where:

  • Cutting Speed = Surface speed in SFM (Surface Feet per Minute)
  • Tool Diameter = Diameter of the cutting tool in inches
  • RPM = Revolutions per minute
  • Feed Rate = Speed in inches per minute (IPM)

Typical Cutting Speeds (SFM):

  • Aluminum: 600-1000 SFM
  • Steel: 100-300 SFM
  • Stainless Steel: 50-150 SFM
  • Brass: 200-400 SFM
  • Plastic: 300-1000 SFM
  • Wood: 500-1500 SFM