CNC speed and feed calculator
Calculate spindle RPM and table feed rate from cutting speed, tool diameter, number of teeth and chip load.
How it is calculated
n = 1000 × Vc ÷ (π × D) RPM. Feed rate Vf = fz × z × n mm/min.
Worked example
Vc 100 m/min, D 10 mm: n = 3183 RPM. With 4 teeth and fz 0.1 mm: Vf = 1273 mm/min.
Steps
- Take Vc from the tool maker data for your material.
- Enter tool diameter, teeth and chip load.
- Set the RPM and feed on the machine, then check the chip.
Frequently asked questions
Where do I get Vc and fz?
From the cutting data sheet of your tool maker and your material.
Does this work for turning?
Use the workpiece diameter for turning, and z = 1 for the feed per revolution.
Is this safe to run directly?
Start 20 to 30 percent below the recommended values and increase while watching the tool.
References
Formulas: standard milling and turning equations (Sandvik and Kennametal cutting data guides).
Estimates for information only. Verify critical values with a qualified engineer or your supplier standards.