Cutting Speed Vc: Formula and Reference Table
Cutting speed Vc = π × d × n / 1000 — how fast the edge passes the material, with a worked example and typical values per material.
The cutting speed formula
Cutting speed Vc (m/min) describes how fast the cutting edge travels through the material: Vc = (π × d × n) / 1000, with d in mm and n in rpm. It is the number every feeds-and-speeds decision starts from.
Worked example
A 63 mm saw blade spinning at 4,000 rpm: Vc = (π × 63 × 4000)/1000 ≈ 792 m/min ≈ 13.2 m/s. A 10 mm end mill at 6,000 rpm gives Vc ≈ 188 m/min — right in the band for wood and MDF.
Two sides of one cut
Spindle speed — RPM, Drehzahl, velocidad de giro — counts how many times per minute the tool turns. Surface speed — cutting speed, Vc, Umfangsgeschwindigkeit, velocidad periférica, vitesse de coupe — measures how fast the cutting edge travels through the material. They describe the same cut and are locked together by one geometric fact: the edge of a bigger cutter covers more distance per revolution.
Why catalogs quote cutting speed, not RPM
Because Vc is diameter-independent, it transfers between machines and tool sizes: a Vc window that suits a coating or a material works for a 3 mm cutter and a 90 mm cutter alike. Each material has a band where the edge runs hot enough to cut cleanly but not so hot that it burns — the numbers every cutting-speed recommendation is really quoting. RPM alone tells you nothing without knowing the diameter.
Typical surface speeds
Mid-range Vc values for CNC routing, from the same presets the tools on this site use: softwood, plywood and MDF ≈ 275 m/min (900 SFM), hardwood ≈ 225 (740), acrylic ≈ 140 (460), ABS ≈ 150 (490), aluminum ≈ 175 (575). Steel with HSS tooling runs far lower, roughly 20–60 m/min. Treat them as starting points and adjust for tool life, finish and machine rigidity.
Vc vs surface feet per minute
US tables list SFM (surface feet per minute). 1 m/min ≈ 3.28 SFM, so a 200 m/min band equals ≈ 656 SFM. Divide SFM by 3.28 to get m/min for the formula above.
Let the calculator do it
The Feeds & speeds converts between metric and imperial automatically and fills Vc from material presets — enter diameter and flutes and read RPM and feed rate directly.