Cutting Speed and RPM Calculator
Convert between surface cutting speed and spindle speed for a given tool or workpiece diameter.
Results
Speed
301.59
m/min
Rotational speed
—
rpm
Diameter
—
mm
What this tool does
Tooling catalogues recommend a cutting speed in metres per minute, but the machine is set in revolutions per minute, and the bridge between them is the diameter. Fill any two of the three fields and the third is calculated.
Formula
vc = π × d × n ÷ 1000
Variables
| Symbol | Meaning | Unit |
|---|---|---|
d | Diameter | mm |
n | Rotational speed | rpm |
vc | Speed | m/min |
VC | Speed | m/min |
N | Rotational speed | rpm |
D | Diameter | mm |
Worked example
- Diameter80 mm
- Rotational speed1200 rpm
- Speed301.59 m/min
Limitations
- Mixing units is the most common source of error. Convert every input to the units shown next to each field before calculating.
- For work that must comply with a standard or be signed off, check the result against the applicable code and have it reviewed by a qualified engineer.