What RPM should I turn wood at?

The general rule is 6,000-9,000 divided by the diameter in inches for the maximum RPM. A 150mm (6 inch) diameter piece should not exceed about 1,500 RPM for roughing. As the piece becomes round and balanced, you can increase speed for finer cuts.

Why is turning speed important?

Too fast causes excessive vibration, loss of control, and risk of the workpiece flying off. Too slow makes clean cuts difficult, especially for end grain. Correct speed gives a smooth cut, controlled tool behaviour, and safe operation.

Should I turn faster or slower for sanding?

Sand at a moderate to high speed (same as finishing cuts). The key is that the surface speed should be high enough for efficient sanding. However, reduce speed for large-diameter bowls to prevent heat build-up which can melt finish and burn the wood.

What is the maximum safe speed for an out-of-round blank?

For square or irregular blanks, use about 60% of the calculated maximum RPM. The imbalance creates vibration that increases stress on the chuck and lathe bearings. Only increase speed once the blank is reasonably round and balanced.

Does wood species affect turning speed?

Not significantly. Hard and soft woods can be turned at similar RPMs for a given diameter. However, very soft woods benefit from slightly higher speeds for cleaner cuts, while wet green wood should be turned slightly slower due to its higher mass.

WoodCalcs

Turning Speed Calculator — Safe RPM for Wood Turning

Calculate safe RPM for wood turning based on blank diameter and operation type.

Operation

Workpiece Diameter

Largest diameter of the blank

How We Calculate This

This calculator determines safe lathe speeds based on workpiece diameter and operation.

The formula

Max RPM = 9,000 / Diameter in inches

Recommended RPM = Max RPM x Operation factor

Operation factors: Roughing = 60%, Shaping = 85%, Finishing = 100%, Sanding = 100%. Roughing uses a lower factor because the blank is typically out of round and unbalanced.

Surface speed (m/s) = pi x diameter (m) x RPM / 60

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify measurements and material quantities before cutting or purchasing.