CNC Milling Speeds, Feeds & Machine Limits Calculator

01 / Setup

Describe your cut

Select a material to load a cutting-data starting point. Verify the exact grade, tool and setup before machining.

Workpiece material

Manual cutting data selected. The loaded numbers are a calculation example.

Tool and cutting data

Cutting speed Vc · m/minFrom the insert or tool maker Feed per tooth fz · mm/toothTarget chip load Cutter diameter D · mm Effective teeth zc · countActive cutting edges on the tool

Pass geometry

Axial depth ap · mm Radial width ae · mm Cutting path length L · mmIn-cut distance for one pass Identical passes countExcludes rapid moves between passes

Machine limits

Machine maximum RPM RPM Tool maximum RPM RPMMarked or specified tool assembly limit Maximum cutting feed mm/minUse cutting-feed capability

Optional power check

Specific cutting force kc · N/mm²Use a supplier value for your material and chip thickness Available spindle power kWPower available at calculated RPM, not motor nameplate power

02 / Result

Machine-ready values

Program spindle—RPM

Program cutting feed—mm/min

Requested RPM—

Feed at selected fz and programmed RPM—

Actual cutting speed—m/min

Actual feed per tooth—mm/tooth

Material removal rate—cm³/min

Total in-cut time—min:sec

Radial engagement—% of diameter

Estimated cutting power—kW, when kc supplied

03 / Check before running

Setup checks

These calculations describe steady cutting only. Verify workholding, tool overhang, entry/exit, coolant, tool grade, machine torque and the final program before machining.

How the numbers are calculated

RPM = 1000 × Vc ÷ (π × D). Feed = RPM × effective teeth × fz. MRR = ap × ae × feed ÷ 1000. Program values round down and respect your machine and tool limits. Time = in-cut length × passes ÷ achieved feed; it excludes rapids, acceleration and tool changes.

Material starting values come from the short CoroMill Dura solid-carbide end-mill chart. At 30–50% radial engagement the app uses the 50% case (ap = 1 × D); above 50% it uses the 100% case (ap = 0.5 × D). Below 30%, enter supplier data for chip thinning. Between listed cutter diameters, fz is interpolated. These are reference values for that tool family, not universal material recommendations.

When kc is supplied, cutting power = ap × ae × feed × kc ÷ 60,000,000. This is a simplified cutting-zone estimate, not motor input power.

Milling formulas — Sandvik Coromant ↗Material cutting-data chart — Sandvik Coromant ↗