Speed & Feed Calculator

Convert cutting speed (SFM) and chip load into spindle RPM and feed rate for any tool and material.

Cutting speed (SFM) and the tool diameter set spindle RPM; RPM, chip load, and the number of flutes set the feed rate. Start from the material’s recommended SFM and chip load, then tune by sound and chip color.

Formula: RPM = (3.82 × SFM) / Ø; Feed (ipm) = RPM × Chip load × Flutes

Worked Example

  1. A 0.500 in 4-flute end mill at 300 SFM, 0.002 in/tooth.
  2. RPM = 3.82 × 300 / 0.5 ≈ 2,292; Feed = 2,292 × 0.002 × 4 ≈ 18.3 ipm.

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