Calculate surface feet per minute from spindle speed and tool diameter.
Using the calculator
Enter values that match the tool, material and operation. Check the unit beside each field before calculating.
Calculation
SFM = π × diameter (in) × RPM ÷ 12.
Reading the result
The result follows the relationship shown on this page. Final shop settings also depend on material, tool geometry, workholding, machine capability, coolant and the actual cut.
Worked example
For example, a 0.5 inch cutter at 8,000 RPM gives about 1,047.20 SFM.