When to use this calculator
Find surface cutting speed from tool diameter and rotational speed. Uses the effective engaged cutting diameter.
Explore the machining feeds, speeds & time calculators for other questions in this topic. For a related calculation, use the Drill Point Length Calculator: Find axial point length for an ideal drill tip.
PUTTING IT INTO PRACTICE
Cutting Speed: a worked example
The values below are an illustrative example, not a recommendation. Replace them with measurements or assumptions that match your question.
| Input | Example value |
|---|---|
| Effective cutting diameter (mm) | 20 |
| Spindle speed (rpm) | 1,000 |
| Result | 62.831853 m/min |
- Check the input labels and enter the example values above.
- Apply the relationship: Cutting speed = π × diameter × rpm/1000.
- The result is 62.831853 m/min, rounded for display.
How to interpret your result
Uses the effective engaged cutting diameter.
Choose cutting speeds and feeds from suitable tooling and material guidance. These tools translate quantities rather than selecting safe cutting conditions. Effective diameter, engagement, machine limits and setup time need separate attention.
Frequently asked questions
Does the spindle-speed calculation recommend a cutting speed?
No. You supply the cutting speed. The tool converts it and a diameter into revolutions per minute.
When is the cutting speed calculator useful?
Find surface cutting speed from tool diameter and rotational speed. Uses the effective engaged cutting diameter.
How do I use the cutting speed calculator?
Enter effective cutting diameter (mm), spindle speed (rpm). The result updates automatically. Use the units shown beside each input; the example values illustrate the method.
Which formula does this calculator use?
Cutting speed = π × diameter × rpm/1000.
What should I check before using the result?
Uses the effective engaged cutting diameter.
How are results rounded?
Scalar numbers display up to six decimal places, with scientific notation for very large or small values. Text, fraction, date and schedule outputs use the format described on the tool. Intermediate calculations use JavaScript floating-point arithmetic. Keep sensible precision for your measurements.
Further reading
For background on this topic, see Sandvik Coromant: machining formulas and definitions ↗. This is a topic reference, not an external review or endorsement of this tool.
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