Wood lathe speed calculator
The spindle speed for a blank of a given diameter, for roughing, general cutting or finishing, from the speed charts in three lathe makers' manuals. Your own lathe's chart is the authority for your lathe.
Spindle speed
450 RPM
Median of 3 sources
Diameter × RPM = 4,500 (a turners’ rule of thumb keeps it near 6,000 roughing, 9,000 finishing).
A starting speed from the lathe makers’ charts; your lathe’s own chart comes first.
Why: For roughing a 10 in blank, the median of 3 lathe makers’ charts is 450 RPM (they span 255–500).
Why these numbers?
The situation
Roughing, a 10 in blank.
From your input: diameter and operation
What that means
JET 450, Grizzly 255, Delta 500 RPM.
So
A turners’ rule of thumb keeps diameter × RPM near 6,000 roughing and 9,000 finishing: 10 × 450 = 4,500.
Traditional rule: Turn a Wood Bowl and Simple Woodturning Tools , sources [4, 5]
The number
The rim of a 10 in blank at 450 RPM moves π × 10 × 450 ÷ 12 = 1,178 ft/min.
Arithmetic: exact by definition
Sources
- JET, JWL-1442VS wood lathe operating instructions: speed by diameter of work (p. 4), read 2026-11-07
- Grizzly, G0632 16" × 42" variable speed wood lathe manual: speed recommendations (Figure 28), read 2026-11-07
- Delta, 46-700 wood lathe manual: recommended spindle speeds, read 2026-11-07
- Turn a Wood Bowl, "Safe Wood Lathe Speed (Calculate, Determine, Adjust RPM)", read 2026-11-07
- Simple Woodturning Tools, "What speed should I be running my lathe?", read 2026-11-07
Wood lathe speed chart
RPM at the middle of each diameter band, from the JET, Grizzly and Delta charts. Delta's chart stops at 12 in, so the 13 in row rests on JET and Grizzly alone, and past 14 in only Grizzly's chart goes on.
| Blank Ø | Roughing | General cutting | Finishing | Basis |
|---|---|---|---|---|
| 1 in | 1,500 | 3,000 | 3,000 | Median of 3 sources |
| 3 in | 760 | 1,500 | 2,300 | Median of 3 sources |
| 5 in | 510 | 1,100 | 1,650 | Median of 3 sources |
| 7 in | 450 | 810 | 1,240 | Median of 3 sources |
| 9 in | 450 | 650 | 1,000 | Median of 3 sources |
| 11 in | 450 | 600 | 850 | Median of 3 sources |
| 13 in | 220 | 455 | 655 | Two sources disagree: JET 450, Grizzly 220 |
The diameter × RPM rule of thumb
Blank diameter in inches × RPM of about 6,000 for roughing, up to about 9,000 for finishing. It is a turners' rule of thumb, not a measurement, so it is shown beside the makers' figure, not used to make it.
Traditional rule, stated by Turn a Wood Bowl and Simple Woodturning Tools
Speed and safety
Turn larger, heavier and out-of-balance work slower: speed drops as the diameter grows, and an unbalanced blank wants a lower speed still.
Delta: change speed only while the lathe is running.
One source: Delta, the maker of that lathe , sources [4]
OSHA requires a wood lathe’s cutting heads to be covered as completely as possible by hoods or shields (1910.213(o)(1)).
One source: OSHA, the federal standard , sources [5]
Sources
- JET, JWL-1442VS wood lathe operating instructions: speed by diameter of work (p. 4), read 2026-11-07
- Laguna Tools, Revo 24|36 lathe manual (troubleshooting: an unbalanced job wants a slower speed), read 2026-11-07
- Woodcraft, "Expert Answers: Safe Turning Speeds" (Mike Kehs, Woodcraft Magazine), read 2026-11-07
- Delta, 46-700 wood lathe manual: recommended spindle speeds, read 2026-11-07
- OSHA, 29 CFR 1910.213, Woodworking machinery requirements, read 2026-11-07