Lathe Speed Calculator

Calculate the recommended RPM for your wood lathe based on workpiece diameter and material type.

Results

Visualization

How It Works

Lathe speed is determined by surface feet per minute (SFM) — the speed of the wood surface passing the tool. Larger diameters need slower RPMs to maintain safe SFM. The formula is RPM = (SFM × 12) / (π × diameter). Softwoods can handle higher SFM (700-900) than hardwoods (500-700). Green wood should turn slower due to imbalance. Always start slower than calculated and increase gradually. For rough blanks or out-of-round stock, reduce speed by 50% until the piece is round.