Milling Horsepower Calculator

Inputs

Width of cut (ae)

Radial width of cut engaged in the material.

Depth of cut (ap)

Axial depth of cut.

Feed rate (Vf)

Programmed table feed rate.

mm/min

Specific cutting force (kc)

Material/tool cutting-force coefficient. Typical values vary strongly by material, tool geometry and chip thickness.

MPa

Machine efficiency (eta)

Allowance from cutting power to required spindle power.

Spindle speed (n)

Spindle RPM used for torque and chip-load checks.

rpm

Flutes (Z)

Effective number of cutting edges.

flutes

Default result

Required spindle power(P_sp)

0.375kW

Cutting power divided by the entered machine efficiency.

Also computed

Cutting power(P_c)0.3kW

Material removal rate(Q)12cm³/min

Spindle torque(T)0.5969N·m

Chip load(fz)0.025mm

Feed per revolution(fn)0.1mm

Efficiency used(eta)0.8

Method notes 3 notes

MRR = width of cut * depth of cut * feed rate.
Cutting power uses P = kc * MRR / 60,000,000 with kc in N/mm^2 and MRR in mm^3/min.
Specific cutting force changes with material, tool geometry, chip thickness, coating, wear and coolant. Treat this as a spindle-load screen, then verify against machine load and toolmaker data.