Spindle Speed Calculator
Calculate spindle speed with explicit inputs and a worked example.
Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Enter a cutting speed suitable for the material, tool and machine.
Example Calculation
- Cutting speed: 100 m/min
- Tool diameter: 10 mm
100 m/min with a 10 mm tool corresponds to about 3,183 rpm.
Frequently asked questions
How do I use this calculator?
Enter cutting speed, tool diameter. The result updates automatically. Use Reset to restore the example values.
What method does it use?
rpm = cutting speed × 1000 / (π × diameter). Enter a cutting speed suitable for the material, tool and machine.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.