# CNC Wood Router Feed and Speeds Calculator

CNC wood router feed and speeds calculator. Pick wood species (oak, maple, cherry, walnut, pine, cedar) or sheet good (Baltic birch, plywood, MDF, melamine) plus bit size and geometry to get router RPM, feed, and chip load.

## What this calculates

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.

## Inputs

- **Wood Species or Sheet Good** — options: Red oak (hard), White oak (hard), Hard maple, Black walnut, Cherry, Poplar (soft hardwood), Pine (soft), Cedar (soft), Douglas fir, Baltic birch plywood, Cabinet-grade plywood, MDF, Melamine on particleboard, OSB, Particleboard — Pick the specific wood or sheet good. Hardwoods run slower SFM with a lighter chip load than softwoods.
- **Router Bit Diameter** (in) — min 0.001 — Cutting diameter of the router bit. Typical hobby sizes 1/8, 1/4, 3/8, 1/2.
- **Bit Geometry** — options: Upcut spiral (fast cut, fuzzy top), Downcut spiral (clean top, chip evacuation issues), Compression (clean both faces, plywood), Straight flute (basic, rare), V-bit (engraving, signs) — Bit geometry affects chip evacuation and finish. Compression is best for veneered plywood.
- **Flutes** — min 1, max 6 — Flute count. 1 flute for fast cut in soft wood, 2 for general use, 3-4 for finishing in hardwood.
- **Router RPM** (RPM) — min 8000, max 40000 — Dial RPM on the router. Makita RT0701 dial 1-6 maps to 10000-30000, Dewalt 611 dial 1-6 to 16000-27000, Bosch 1617 dial 1-6 to 8000-25000.
- **Depth of Cut per Pass** (in) — min 0 — Z-depth per pass. Conservative: 25 percent of bit diameter. Aggressive: 50 percent in softwood.

## Outputs

- **Calculated Ideal RPM** (RPM) — RPM the chart SFM would target if the router could spin that fast.
- **Run RPM** (RPM) — RPM you will actually run (the smaller of calculated and router setting).
- **Feed Rate** (IPM) — Feed rate in inches per minute at the run RPM.
- **Feed Rate (metric)** (mm/min) — Feed rate in mm/min for metric CNC controllers.
- **Chip Load per Tooth** (IPT) — Feed per flute per revolution used in the feed calculation.
- **Material Removal Rate** (in^3/min) — Approximate wood removal rate: DOC x bit diameter x feed rate.

## Details

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 goodCarbide SFMChip load 1/4" (IPT)Feed at 18,000 RPM, 2 flutes
  
  
    Red oak22000.008288 IPM
    White oak22000.008288 IPM
    Hard maple21000.008288 IPM
    Black walnut23000.009324 IPM
    Cherry23000.008288 IPM
    Poplar26000.010360 IPM
    Pine28000.012432 IPM
    Cedar29000.013468 IPM
    Douglas fir28000.012432 IPM
    Baltic birch plywood23000.009324 IPM
    Cabinet plywood23000.009324 IPM
    MDF25000.010360 IPM
    Melamine on particleboard24000.008288 IPM
    OSB22000.010360 IPM
    Particleboard24000.011396 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.

## Frequently Asked Questions

**Q: How do I calculate CNC wood router feed and speeds?**

A: Ideal RPM = (SFM x 12) / (pi x bit diameter). Feed rate (IPM) = RPM x chip load x flutes. For red oak (2,200 SFM), 1/4 inch 2 flute upcut carbide at 0.008 IPT: ideal RPM = 33,614; at 18,000 router RPM, feed = 288 IPM. This CNC wood router feed and speeds calculator picks the right SFM and chip load for your specific wood species.

**Q: What feed rate for 1/4 inch bit in oak on a CNC router?**

A: A 1/4 inch 2 flute carbide upcut in red oak at 18,000 RPM with 0.008 IPT chip load runs at 288 IPM (7,315 mm/min). At 24,000 RPM the feed climbs to 384 IPM. Drop to 0.006 IPT for tighter finish and 216 IPM feed. The CNC wood router feed and speeds calculator auto-computes both the RPM and the feed.

**Q: How does bit geometry change the feed rate?**

A: Upcut runs at 100 percent of chart chip load. Downcut runs at 75 percent because chips trap in the cut. Compression runs at 85 percent and is best for veneered plywood. Straight flute runs at 90 percent. V-bits run at 50 percent because only the tip is cutting. This calculator automatically scales chip load by bit type.

**Q: What router RPM for hardwood vs softwood?**

A: SFM is higher for softwood, so ideal RPM is higher too. Red oak wants 33,614 RPM on a 1/4 inch bit; pine wants 42,765 RPM. Most routers cap at 24,000-30,000 RPM, so both cases run at the router max. The feed rate is higher in softwood because the chip load is higher (0.012 vs 0.008 IPT). Use the max router RPM and let the chip load do the work.

**Q: What chip load should I use for Baltic birch plywood?**

A: 0.009 IPT on a 1/4 inch bit, which gives 324 IPM feed at 18,000 RPM with 2 flutes. Use a compression bit for veneered Baltic birch to protect both top and bottom faces from tear-out. The CNC wood router feed and speeds calculator applies the 0.85x compression adjustment automatically: effective chip load 0.0077 IPT, feed 275 IPM at 18,000 RPM.

**Q: Does this calculator work for MDF and melamine?**

A: Yes. MDF runs 2,500 SFM with 0.010 IPT; melamine runs 2,400 SFM with 0.008 IPT (melamine is abrasive and dulls bits, so lighter chip load extends bit life). Use a carbide compression bit for melamine to avoid chipping the hard face. This CNC wood router feed and speeds calculator handles both materials with their own SFM and chip load values.

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Source: https://vastcalc.com/calculators/physics/cnc-wood-router-feed-and-speeds
Category: Physics
Last updated: 2026-04-08