Drilling Formula Interactive Calculator
Solve for any subject variable in bold by entering values in the boxes on the left side of the equation and clicking the "Calculate" button. The solution will appear in the box on the right side of the equation. To enter a value, click inside the boxes containing the "Enter" prompts.
 
Legend:
D - Drill diameter (in inches) Z - Number of flutes
SURFACE FEET PER MINUTE (SFM)

Enter RPM Enter D
X X /12 =
REVOLUTIONS PER MINUTE (RPM)
Enter SFM Enter D
X (12/ ) / =
INCHES PER REVOLUTION FEED RATE (IPR)
Enter IPT Enter Z
X =
INCHES PER MINUTE FEED RATE (IPM)
Enter RPM Enter IPR
X =
INCHES PER TOOTH FEED RATE (IPT)
Enter IPM Enter RPM Enter Z
/ / =
CUBIC INCHES PER MINUTE METAL REMOVAL RATE (in³/min)
Enter RPM Enter IPR Enter D
X X =