Material Removal Rate Calculator Formula

Understand the math behind the material removal rate calculator. Each variable explained with a worked example.

Formulas Used

Material Removal Rate

mrr = depth_of_cut * width_of_cut * feed_rate / 1000

MRR

mrr_mm3 = depth_of_cut * width_of_cut * feed_rate

Variables

VariableDescriptionDefault
depth_of_cutAxial Depth of Cut (ap)(mm)3
width_of_cutRadial Width of Cut (ae)(mm)20
feed_rateTable Feed Rate (Vf)(mm/min)400

How It Works

Material Removal Rate in Milling

MRR quantifies how fast material is being removed, which directly relates to productivity and power consumption.

Formula

MRR = ap x ae x Vf

where ap is the axial depth of cut, ae is the radial width of cut, and Vf is the table feed rate. The result in mm^3/min can be divided by 1000 for cm^3/min.

Worked Example

Milling with 3 mm depth, 20 mm width, at 400 mm/min feed.

depth_of_cut = 3width_of_cut = 20feed_rate = 400
  1. 01MRR = 3 x 20 x 400 = 24,000 mm^3/min
  2. 02MRR = 24,000 / 1000 = 24 cm^3/min
  3. 03For steel with specific cutting energy of 2.5 W-s/mm^3, power = 24000/60 x 2.5 = 1000 W = 1 kW at spindle.

Ready to run the numbers?

Open Material Removal Rate Calculator