Milling Calculator

How it works

1. 1Enter cutter diameter and spindle speed — the calculator finds cutting speed Vc = π·D·N / 1000 in m/min.
2. 2Enter feed per tooth and number of flutes — table feed rate Vf = N·fz·z is computed in mm/min.
3. 3Enter radial width ae and axial depth ap — MRR = ae·ap·Vf / 1000 gives chip volume removed per minute in cm³/min.

Use cases

• CNC machinists verifying programmed feed and speed parameters before cutting a new material.
• Process engineers comparing material removal rates across different cutter sizes and strategies.
• Tooling application engineers selecting flute count and feed per tooth to hit a target cycle time.

Frequently asked questions

What is the formula for cutting speed in milling?

Cutting speed Vc = π · D · N / 1000, where D is the cutter diameter in mm and N is the spindle speed in rpm. The result is in m/min. For example, a 12 mm cutter at 3000 rpm gives Vc = π × 12 × 3000 / 1000 ≈ 113 m/min.

How is table feed rate different from feed per tooth?

Feed per tooth (fz) is the chip load per cutting edge per revolution, typically 0.01–0.15 mm for end mills. Table feed rate Vf = N·fz·z converts this to the linear speed the workpiece moves in mm/min, so machine axes can be programmed directly.

How do I use MRR to check if my spindle can handle the cut?

Cutting power Pc ≈ MRR × kc ÷ 60 000 (kW), with MRR in cm³/min and kc the specific cutting force in N/mm². Compare that with your machine’s spindle power at the selected rpm. If estimated power exceeds 80 % of rated spindle power, reduce ae, ap, or Vf.