Milling Feeds and Speeds Calculator

Formula and method

Metric: n=1000·Vc/(π·Dcap), with Vc in m/min and Dcap in mm. Imperial: n=12·Vc/(π·Dcap), with Vc in ft/min and Dcap in inches. Vf=n·fz·Zeff; fn=fz·Zeff. Feed uses the length unit of fz; 1 in=25.4 mm.

Worked example

Example: Dcap=10 mm, Vc=150 m/min, fz=0.05 mm and Zeff=4 give about 4774.648 rpm, 954.930 mm/min table feed and 0.2 mm/rev. Defaults are example inputs only.

Assumptions and limits

For ball-nose, round-insert and large-radius cutters, Dcap may differ from nominal diameter. Use the actual depth and cutter documentation; no automatic correction is made.
Use the effective cutting tooth count defined in the cutter documentation. Do not substitute flute count or the number of teeth engaged at an instant unless the manufacturer defines it that way.
fz is not universally the maximum chip thickness. Material, coating, radial chip thinning, engagement, coolant and depth are not inferred. Material removal rate and power are not calculated.
Outputs are not rounded to machine settings. If actual rpm differs, recalculate feed accordingly. Results do not establish safe machine, workholding or cutter capability and are not a turning calculator.

Frequently asked questions

Why can’t I obtain rpm from material alone?

Cutting speed and feed per tooth also depend on cutter model, material condition, coating, coolant, depth and setup. This page only converts Vc and fz you have selected from the relevant cutter documentation.

References

Sandvik Coromant — Milling formulas and definitions

Milling Feeds and Speeds Calculator practical guide and common questions

What does Milling Feeds and Speeds Calculator calculate?

This is a milling data converter. Supply Vc and fz for the actual cutter and operation; no values are recommended by material. Dcap is the effective cutting diameter at the actual depth of cut. Metric: n=1000·Vc/(π·Dcap), with Vc in m/min and Dcap in mm. Imperial: n=12·Vc/(π·Dcap), with Vc in ft/min and Dcap in inches. Vf=n·fz·Zeff; fn=fz·Zeff. Feed uses the length unit of fz; 1 in=25.4 mm.

When is this useful?

Example: Dcap=10 mm, Vc=150 m/min, fz=0.05 mm and Zeff=4 give about 4774.648 rpm, 954.930 mm/min table feed and 0.2 mm/rev. Defaults are example inputs only.

How do I enter the inputs?

Enter the inputs for Milling Feeds and Speeds Calculator: Input units, Effective cutting diameter Dcap, Effective cutting diameter Dcap, Supplied cutting speed Vc, Supplied cutting speed Vc, Supplied feed per tooth fz, Supplied feed per tooth fz, Effective cutter teeth Zeff (integer). Calculate, check the units and assumptions, then copy or download the results.

How should I interpret the results?

For ball-nose, round-insert and large-radius cutters, Dcap may differ from nominal diameter. Use the actual depth and cutter documentation; no automatic correction is made. Use the effective cutting tooth count defined in the cutter documentation. Do not substitute flute count or the number of teeth engaged at an instant unless the manufacturer defines it that way. fz is not universally the maximum chip thickness. Material, coating, radial chip thinning, engagement, coolant and depth are not inferred. Material removal rate and power are not calculated. Outputs are not rounded to machine settings. If actual rpm differs, recalculate feed accordingly. Results do not establish safe machine, workholding or cutter capability and are not a turning calculator.

Where are my inputs processed?

Milling Feeds and Speeds Calculator runs in this browser. Inputs are not uploaded to a calculation server; copying and CSV download require your action. The existing site analytics and advertising still load.