Wood Speeds & Feeds Calculator - CNC Router Feeds for Wood, Plywood, MDF & Acrylic

How It Works

1. Select Material

   Choose your workpiece material from the list: softwood (pine, cedar, spruce), hardwood (oak, maple, cherry), walnut/mahogany, plywood (Baltic birch, CDX), MDF, particle board/melamine, bamboo, acrylic (cast or extruded), HDPE/Delrin/UHMW, foam board, carbon fiber/G10, or aluminum on a CNC router. Each material row lists a starting chip-load range, SFM range, and depth-of-cut factor.

2. Choose Tool Type and Size

   Select your bit type: straight flute, spiral upcut, spiral downcut, compression (up/down), V-bit (30/60/90/120 degree), or ball nose. Enter the cutter diameter (common sizes: 1/8", 1/4", 3/8", 1/2") and number of flutes (typically 1 or 2 for wood, sometimes 3 for finishing passes).

3. Select Router or Spindle

   Choose from built-in presets: DeWalt DWP611 (16,000-27,000 RPM), Makita RT0701C (10,000-30,000 RPM), VFD spindles (0.8/1.5/2.2 kW), or custom RPM entry. The preset sets the RPM slider range and lets the calculator warn you if the screened RPM is outside the listed router range.

4. Set Depth and Stepover

   Enter the axial depth of cut (DOC) and radial stepover (WOC). The calculator shows a maximum-DOC prompt as a multiple of cutter diameter from the material row (e.g. 0.5x for hardwood, 1x for softwood/MDF, 2x for foam) and a typical stepover hint by operation.

5. Review Results and Warnings

   See screened RPM, feed rate (IPM), chip load per tooth, material removal rate, and status badges. Warning indicators flag burn, chip-out, heat, dust, deflection, and cutter-chart review items, but they do not approve the setup for the machine or job.

Built For

• CNC hobbyists with desktop routers (Shapeoko, X-Carve, MPCNC) reviewing conservative starting feed and speed prompts for first projects
• Sign makers optimizing V-bit carving parameters for clean lettering in hardwood and HDU sign foam
• Cabinet makers programming CNC routers for dadoes, rabbets, and panel processing in plywood and MDF
• Woodworkers cutting hardwood inlays and joints who need to avoid burning and tear-out at tight tolerances
• Makerspaces and schools setting up CNC routers with conservative starting parameters for student use
• CNC operators transitioning from metal machining to wood routing who need material-specific guidance

Features & Capabilities

Router Presets

Built-in RPM ranges for the DeWalt DWP611, Makita RT0701C, and common VFD spindles (0.8 kW, 1.5 kW, 2.2 kW), plus custom RPM entry. The calculator warns when the screened RPM falls outside the listed range - verify against the actual machine nameplate.

Material-Specific Starting Rows

Starting-point chip-load, SFM, and DOC rows per material category. The exact species, sheet product, plastic grade, cutter geometry, coating, and manufacturer chart can change the usable setup.

Burn & Chip-Out Review Prompts

Warning prompts flag settings associated with rubbing, burn, veneer chip-out, acrylic heat, MDF dust, or poor chip evacuation. Treat them as review items, not proof that the correction is safe for the machine.

Tool Type Prompts

Context rows for upcut, downcut, compression, V-bit, ball-nose, and straight router bits. Use the exact cutter datasheet and job setup before choosing a production path.

Depth-of-Cut Prompts

Maximum-DOC prompts based on cutter diameter and the material row factor, with deflection warnings for small-diameter bits at aggressive depths. Conservative starting points for hobby-class CNC routers.

Feed Rate Screening

Calculates the feed rate from chip load, RPM, and flute count, and badges the result against the listed material chip-load range so you can identify values that need cutter-chart and test-cut review.

Assumptions

• Chip-load rows assume sharp carbide end mills in good condition; worn, chipped, coated, specialty, or manufacturer-specific cutters require the exact cutter chart.
• Router presets assume the router is operating at the indicated RPM under no-load conditions - actual RPM drops under cutting load, especially on trim routers below 2 HP.
• Depth-of-cut prompts assume machine rigidity and workholding are adequate for screening only; hobby-class machines and flexible fixtures may need much lighter test cuts.
• Material categories group similar species together - actual cutting properties vary within categories (e.g., hard maple vs soft maple within "hardwood").
• Feed rate calculations assume consistent workholding; loose, thin, warped, or vibrating workpieces require setup review beyond the calculator.

Limitations

• Does not account for specific wood grain orientation (end grain, cross grain, long grain) which significantly affects chip formation and surface quality.
• Burn and chip-out warnings are heuristic thresholds, not measured values - actual burn onset depends on moisture content, resin content, and tool sharpness.
• Does not model tool deflection quantitatively - only flags when DOC exceeds a diameter-based rule of thumb.
• Acrylic and plastic rows are broad starting prompts - extruded versus cast acrylic, HDPE, Delrin, UHMW, and composites behave differently and require cutter-chart/test-cut review.
• Does not cover specialized tooling (diamond-coated, PCD, indexable insert routers) which have different chip load ranges than solid carbide.

References

• Machinery's Handbook (31st Edition) - cutting speed, feed, and chip load fundamentals for wood and non-ferrous materials.
• Onsrud Cutter Technical Guide - CNC router chip-load source pointer for wood, plastics, and composites by material and tool type.
• Amana Tool CNC Router Bit Selection Guide - feed and speed source pointer for hardwood, softwood, plywood, MDF, and acrylic.
• Forest Products Laboratory - Wood Handbook (FPL-GTR-190) - mechanical properties and machinability of wood species.
• CNC Cookbook - practical CNC router feeds and speeds methodology for hobby and mid-range machines.

Frequently Asked Questions