Drilling RPM Calculator
Spindle speed and feed rate for drilling from drill diameter, cutting speed and feed per revolution.
Inputs
mm
m/min
HSS: steel 20–30 · aluminium 60–100. Carbide: steel 70–120.
mm/rev
Results
- Spindle speed
- 796 rpm
- Feed rate
- 119.4 mm/min
- Feed rate
- 4.7 in/min
Formula
n = 1000 × Vc ÷ (π × D)
Feed rate = n × f
Assumptions & limits
- Start from the tool maker's recommended Vc and feed; reduce for deep holes (> 3×D).
Worked example
1000 × 25 ÷ (π × 10) = 796 rpm × 0.15 = 119.4 mm/min.