CNC Speeds & Feeds Calculator

Accurate spindle speed RPM and table feed rate calculation for CNC milling and routing.

Tool Endmill Diameter (inches):

Workpiece Material (Surface Speed SFM):

Number of Tool Flutes (Cutting Edges):

Chip Load per Tooth (inches/tooth):

Result

12,224 RPM | 73.3 IPM

1/4" End Mill (3 Flutes) | 6061 Aluminum

Methodology & Formulas

RPM = (SFM × 3.82) / Diameter
Feed (IPM) = RPM × Flutes × Chip Load

Optimizing speeds and feeds is critical to achieving superior surface finish, eliminating chatter, and preventing premature tool breakage or cutter overheating in CNC machining centers.