Saw blade and grinding wheel rim speed calculator
The surface speed of a saw blade, router bit or grinding wheel from its diameter and RPM.
How it works
Rim speed = π × diameter × RPM. With the diameter in feet the result is in surface feet per minute (SFPM). A 10-inch blade at 4,800 RPM moves about 12,570 ft per minute at the teeth, or around 143 mph. Every blade and wheel has a maximum safe RPM printed on it. Never run it on a tool that spins faster.
Quick reference
| 7¼ in circular saw | 5,800 RPM | ~11,000 SFPM |
| 10 in table saw | 4,800 RPM | ~12,600 SFPM |
| 4½ in angle grinder | 11,000 RPM | ~13,000 SFPM |
| 12 in miter saw | 4,000 RPM | ~12,600 SFPM |
Typical no-load speeds. Check the tool nameplate.
Questions
Why does it matter?
A wheel or blade run above its rating can break apart. Grinding wheels are a known cause of eye and face injuries.
Sources
Injury data for these tools
Grinders, buffers & polishersLaceration40,246
Other power saws (miter, tile, unspecified)Laceration33,665
Table sawsLaceration31,444
Circular sawsLaceration10,961
Band sawsLaceration2,141
RoutersLaceration1,812ER visits in 2025
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