Drill speed and feed calculator converts drill diameter, target surface speed, and feed per revolution into spindle RPM and feed rate in one step.
Get spindle speed and feed rate for a twist drill from diameter, target surface speed, and feed per revolution.
RPM = (SFM x 3.82) / D. Feed rate = RPM x feed per revolution. Drills feed per revolution, not per tooth, since both flutes engage together.
How it works
Twist drills run slower surface speeds than end mills because the chisel edge at the tip does not cut cleanly, it scrapes. Starting from a conservative SFM for the material and converting straight to RPM and feed keeps the drill from burning up on entry.
FAQ
Why is drill SFM lower than milling SFM for the same material? The center of a twist drill does not have a true cutting edge, so the whole tool runs slower to protect that chisel point.
Related Guides
CNC Calculators · SFM Calculator · Peck Drilling Calculator
How it works
This combines the two core drilling calculations, RPM from SFM and diameter, then feed rate from RPM and feed per revolution, since both usually get set together at the start of programming a new hole operation. Drills feed per revolution, not per tooth, because both cutting edges engage the material together as the drill turns and advances.
FAQ
How is this different from the separate Drill RPM and Drill Feed calculators? It’s the same underlying formulas combined into a single step for convenience when you want both results from one set of inputs, rather than calculating RPM first and feeding it into a second calculator.
Related Guides
CNC Calculators · Drill RPM Calculator · Drill Feed Calculator