Work out material removal rate instantly with clear inputs, formula shown and shareable results.
Removal rate is simply the cross-section being cut times the speed it is swept: width times depth times feed. Multiplying by the material's unit power, about 1.0 hp per cubic inch per minute for mild steel and 0.3 for aluminium, gives the spindle power the cut demands.
Removal rate
MRR = width x depth x feed rate
Power
hp = MRR x unit power for the material
MRR = width x depth x feed rate. Removal rate is simply the cross-section being cut times the speed it is swept: width times depth times feed.
Power demand is proportional to removal rate. Doubling depth doubles the horsepower required, and a small mill runs out of spindle power long before the tool runs out of strength.
This calculator takes 4 inputs: Width of cut, Depth of cut, Feed rate, Unit power for material. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.