CNC Feed Rate & Chip Load Calculator
Optimize your CNC router and milling parameters. Calculate the precise Feed Rate, Chip Load (Inches Per Tooth), Spindle RPM, and Plunge Rate for your cutter geometry and material to eliminate tool deflection, chatter, and burning.
Calculated Machining Speeds
Machining Science: Why Proper Chip Load Matters
Chip Load represents the thickness of the material chip removed by each cutting edge (flute) as the tool rotates. Maintaining the correct chip load is crucial for CNC longevity and edge quality:
- Too Small (Rubbing & Overheating): If feed rate is too low or RPM is too high, the tool rubs rather than shears the material. Friction creates extreme localized heat, burning wood, melting acrylic, and dulling carbide cutting edges in minutes.
- Too Large (Tool Breakage & Chatter): Excessive chip load exerts excessive cutting forces, causing spindle deflection, severe chatter marks on the sidewalls, and snapping small 1/8" or 1/4" end mills.
• Feed Rate (IPM) = Spindle RPM × Number of Flutes × Chip Load (IPT)
• Chip Load (IPT) = Feed Rate (IPM) ÷ (Spindle RPM × Number of Flutes)
• Material Removal Rate (MRR) = Cut Depth (DOC) × Stepover Width (WOC) × Feed Rate (IPM)
How Dirty Vector DXF Files Sabotage CNC Feed Rates
Even with the perfect calculated feed rate, your CNC machine will fail if the vector file contains thousands of tiny, fragmented line segments (the hallmark of bad raster auto-tracing). CNC motion controllers (GRBL, Mach3/4, Masso, LinuxCNC) must decelerate at every node vertex. A segmented 20,000-node DXF causes constant machine stuttering, reducing actual feed rate to 15% of target and burning your workpiece. Clean, continuous Bezier arcs maintain smooth continuous velocity at full programmed IPM.