CNC Machinist Calculators & Reference Tools

CNC Machinist Calculators

Shop-floor calculators for everyday CNC work.

Available Tools:
  • Feed Rate Calculator (IPR ↔ IPM)
  • Surface Speed Calculator (SFM ↔ RPM)
  • Tap Feed Calculator (Rigid Tapping)

Feed Rate Calculator

Use either direction depending on what you know.

IPR → IPM

Enter RPM and IPR to calculate IPM.





IPM → IPR

Enter RPM and IPM to calculate IPR.





Surface Speed Calculator

Calculate RPM from SFM and diameter.





Tap Feed Calculator

For rigid tapping, feed rate must match thread pitch. Select a thread below.

Imperial Tapping

Enter RPM and select a thread. Feed is based on TPI.





Metric Tapping

Enter RPM and select a thread. Feed is based on pitch.





Need tap drill sizes?
View Tap Drill Chart →
Built by Cinci CNC in Cincinnati, Ohio. We make practical tooling and shop-floor solutions for real machining work.