CNC Wood Router Feed and Speeds Calculator
A CNC wood router feed and speeds calculator tuned for hobby routers and DIY woodworking shops. Pick a specific wood (red oak, hard maple, walnut, cherry, poplar, pine, cedar, Douglas fir) or sheet good (Baltic birch, cabinet plywood, MDF, melamine, OSB), the router bit diameter, and the bit geometry (upcut, downcut, compression, straight, V-bit). The calculator returns router RPM, feed rate in IPM and mm/min, chip load, and material removal rate. Everything is capped at your router's actual RPM, so the output is a setting you can dial in right now.
Wood router feed and speeds formulas
- Ideal RPM = (SFM x 12) / (pi x bit diameter in inches).
- Run RPM = min(ideal RPM, router max RPM). Most hobby routers top at 24,000-30,000; many bit + wood combos want more RPM than that.
- Feed rate (IPM) = run RPM x chip load per tooth x flute count.
- mm/min = IPM x 25.4.
- Material removal rate (in^3/min) = depth of cut x bit diameter x feed rate.
Example: 1/4 inch 2 flute upcut spiral in red oak at 2,200 SFM, 0.008 IPT baseline. Ideal RPM = 33,614. At 18,000 router RPM: feed = 18,000 x 0.008 x 2 = 288 IPM. In cedar at 2,900 SFM, 0.013 IPT the calculated ideal RPM is 44,300; you still run at 18,000, but feed climbs to 18,000 x 0.013 x 2 = 468 IPM because cedar takes a bigger chip.
Feeds and speeds by wood species
| Wood or sheet good | Carbide SFM | Chip load 1/4" (IPT) | Feed at 18,000 RPM, 2 flutes |
|---|---|---|---|
| Red oak | 2200 | 0.008 | 288 IPM |
| White oak | 2200 | 0.008 | 288 IPM |
| Hard maple | 2100 | 0.008 | 288 IPM |
| Black walnut | 2300 | 0.009 | 324 IPM |
| Cherry | 2300 | 0.008 | 288 IPM |
| Poplar | 2600 | 0.010 | 360 IPM |
| Pine | 2800 | 0.012 | 432 IPM |
| Cedar | 2900 | 0.013 | 468 IPM |
| Douglas fir | 2800 | 0.012 | 432 IPM |
| Baltic birch plywood | 2300 | 0.009 | 324 IPM |
| Cabinet plywood | 2300 | 0.009 | 324 IPM |
| MDF | 2500 | 0.010 | 360 IPM |
| Melamine on particleboard | 2400 | 0.008 | 288 IPM |
| OSB | 2200 | 0.010 | 360 IPM |
| Particleboard | 2400 | 0.011 | 396 IPM |
Bit geometry changes the feed
A CNC wood router feed and speeds calculator has to account for bit geometry. An upcut spiral pulls chips up out of the cut, handles full chart chip load, and leaves a slightly fuzzy top face. Run upcuts at 100 percent chart IPT. A downcut spiral leaves a clean top face but packs chips into the cut, so run at 75 percent of chart IPT and step down cautiously. Compression bits (upcut tip, downcut shank) balance both faces on plywood and veneered panels at 85 percent of chart IPT. Straight flutes are rare on modern CNC routers; run at 90 percent. V-bits are for engraving and signage; they run at 50 percent chip load and much lower depth per pass. This calculator automatically scales chip load to bit type.
Chip load vs bit diameter
Small bits cannot take full chart IPT because the flute pocket is small and chips pack quickly. The calculator scales chip load to 50 percent for 1/8 inch and smaller bits, 75 percent for 3/16 inch, 100 percent for 1/4 inch (chart value), and up to 125 percent for 3/4 inch and larger. A CNC wood router feed and speeds calculator that does not scale chip load for bit size will break small bits in hardwood.
Depth of cut for hobby routers
A CNC wood router feed and speeds calculator should pair with a sensible depth of cut. Conservative rule: depth per pass equals 25 percent of bit diameter in hardwood, 50 percent in softwood and MDF. For a 1/4 inch bit that is 0.0625 inch in oak and 0.125 inch in pine. More rigid machines (Avid, ShopBot, Laguna) can double those numbers; hobby wheel-based machines should halve them. The material removal rate output on this calculator helps you compare machine setups.
Router dial to RPM map
Most hobby CNC wood routers use a trim router with a dial, not a variable-frequency spindle. Makita RT0701 dial 1-6 maps to 10,000, 12,000, 17,000, 22,000, 27,000, 30,000 RPM. Dewalt 611 dial 1-6 maps to 16,000, 18,200, 20,400, 22,600, 24,800, 27,000 RPM. Bosch 1617EVS dial 1-6 maps to 8,000, 12,000, 15,000, 19,000, 22,000, 25,000 RPM. Pick the dial setting that lands closest to the calculator's ideal RPM without going under 60 percent of it; the feed rate will compute correctly at the router RPM you enter.