CNC milling combines spindle speed, feed rate, chip load, cutter geometry and engagement. Use the dedicated calculators for the arithmetic and this page as an operating reference.
Milling calculation chain
Start with cutting speed and tool diameter to calculate RPM. Then calculate feed from RPM, flute count and chip load per tooth. Use radial engagement and axial depth for the MRR estimate when appropriate.
Engagement matters
Slotting and light radial engagement place different demands on the cutter. Keep the toolmaker chip-load method attached to the engagement condition instead of assuming one value fits every toolpath.
Rigidity and tool reach
Stick-out, holder condition, runout and workholding can change the stable cutting range. Diagnose the physical setup before changing a correct calculation.
Related tools
Open the Feed & Speed Calculator, Chip Load Calculator or MRR Calculator.