CNC Calculators

Section in active development

A growing collection of calculators for everything from feeds and speeds to G-code arc math. Built for machinists, programmers, and shop owners who need the right number fast — without the textbook lookup. Categories below show the planned scope; individual calculators ship as they’re built.

📐 Lathe 16

Bar Stock Length CalculatorHome » CNC CalculatorsCALCULATOR Work out how many parts a length of bar stock will yield once facing and parting […]Constant Surface Speed CalculatorHome » CNC CalculatorsCALCULATORConstant surface speed (CSS) calculates the spindle RPM needed to hold a target SFM at the current […]Facing Cycle Time CalculatorHome » CNC CalculatorsCALCULATORFacing cycle time estimates how long a facing pass takes based on the part radius, feed rate, […]Grooving Time CalculatorHome » CNC CalculatorsCALCULATORGrooving (plunge) cycle time estimates how long a peck-plunge groove takes from groove depth, plunge feed rate, […]ID Boring Time CalculatorHome » CNC CalculatorsCALCULATORID boring cycle time estimates how long an internal boring pass takes from bore length, clearance, feed […]Knurling CalculatorHome » CNC CalculatorsCALCULATORKnurling calculator finds the whole number of knurl teeth that fit a part’s circumference at a given […]Lathe Operation Time CalculatorHome » CNC CalculatorsCALCULATOR OperationFacingOD TurningParting-Off Stock diameter (in) Length of cut (in) Approach/clearance (in) Feed rate (in/rev) Spindle speed […]Lathe Speed and Feed CalculatorHome » CNC CalculatorsCALCULATOR Get spindle speed and feed rate for turning from workpiece diameter, target surface speed, and feed […]OD Turning Time CalculatorHome » CNC CalculatorsCALCULATOROD turning time estimates cycle time for an outside-diameter turning pass from cut length, feed rate, approach […]Parting-Off Time CalculatorHome » CNC CalculatorsCALCULATORParting-off time estimates how long it takes to cut through stock using a parting (cut-off) tool, based […]Taper CalculatorHome » CNC CalculatorsCALCULATOR Large diameter (in) Small diameter (in) Length between diameters (in) —Taper per foot —Taper per inch […]Thread Turning CalculatorHome » CNC CalculatorsCALCULATORThread turning depth calculates the total infeed depth for cutting an external 60° V-thread on a lathe […]Threading Compound Infeed CalculatorHome » CNC CalculatorsCALCULATOR Find the dial reading to feed in along an angled compound slide so the full thread […]Threading Pass CalculatorHome » CNC CalculatorsCALCULATOR Total thread depth, radial (in) Number of passes —First pass depth —Final pass depth Pass Depth […]Turning Feed CalculatorHome » CNC CalculatorsCALCULATORTurning feed rate converts spindle RPM and a chosen feed per revolution into the linear feed rate […]Turning RPM CalculatorHome » CNC CalculatorsCALCULATORTurning RPM sets spindle speed from a target surface speed (SFM) and the current stock diameter being […]

📐 CNC Router 14

Acrylic Feed CalculatorHome » CNC CalculatorsCALCULATOR Spindle Speed (RPM) Number of Flutes Recommended Feed Rate (Acrylic)— Acrylic chip load default 0.005 in/flute […]Engraving Time CalculatorHome » CNC CalculatorsCALCULATOR Estimate how long an engraving job will run from the total tool path length, your feed […]MDF Feed CalculatorHome » CNC CalculatorsCALCULATOR Spindle Speed (RPM) Number of Flutes Recommended Feed Rate (MDF)— MDF chip load default 0.018 in/flute. […]Plywood Feed CalculatorHome » CNC CalculatorsCALCULATOR Spindle Speed (RPM) Number of Flutes Recommended Feed Rate (Plywood)— Plywood chip load default 0.010 in/flute […]Router Feed Rate CalculatorHome » CNC CalculatorsCALCULATOR Spindle Speed (RPM) Chip Load per Flute (in) Number of Flutes Feed Rate (IPM)— Feed Rate […]Router RPM CalculatorHome » CNC CalculatorsCALCULATOR Cutting Speed (SFM) Bit Diameter (in) Spindle Speed— RPM = (SFM × 3.82) / Bit Diameter. […]Router Speed and Feed CalculatorHome » CNC CalculatorsCALCULATOR Get spindle speed and feed rate for a CNC router bit cutting wood, MDF, or plastic, […]Sheet Nesting Yield CalculatorHome » CNC CalculatorsCALCULATOR Get a quick estimate of how many rectangular parts fit on a sheet in a simple […]Sign-Making Time CalculatorHome » CNC CalculatorsCALCULATOR Total Toolpath Length (in) Feed Rate (ipm) Number of Plunges Time per Plunge (sec) Estimated Job […]Tab and Bridge Spacing CalculatorHome » CNC CalculatorsCALCULATOR Part perimeter (in) Target max spacing between tabs (in) Tab width (in) —Number of tabs —Actual […]Tab Thickness CalculatorHome » CNC CalculatorsCALCULATOR Work out how thick to leave retention tabs when cutting parts out of sheet stock, so […]V-Bit Carving Depth CalculatorHome » CNC CalculatorsCALCULATOR Solve forWidth (from desired depth)Depth (from desired width) V-bit included angle (deg) Desired depth (in) Bit […]V-Bit Width CalculatorHome » CNC CalculatorsCALCULATOR V-Bit Included Angle (°) Plunge Depth (in) Resulting Cut Width— Cut Width = 2 × Depth […]Wood Chip Load CalculatorHome » CNC CalculatorsCALCULATOR Wood TypeSoftwood (0.012 in)Hardwood (0.008 in)MDF (0.018 in)Plywood (0.010 in) Number of Flutes Spindle Speed (RPM) […]

📐 Geometry & Shop Math 14

Arc CalculatorHome » CNC CalculatorsCALCULATOR Radius (in) Arc Angle (°) Arc Length— Chord Length— Arc Length = Radius × Angle (rad). […]Bolt Circle CalculatorHome » CNC CalculatorsCALCULATOR Enter the bolt circle radius (or diameter), the number of holes, and a starting angle, and […]Bolt Circle Coordinate GeneratorHome » CNC CalculatorsCALCULATOR Bolt Circle Diameter (in) Number of Holes Start Angle (°) Holes are evenly spaced at 360/N […]Chamfer CalculatorHome » CNC CalculatorsCALCULATORChamfer calculator converts a target chamfer angle and one known leg (depth or width) into the other […]Chord Length CalculatorHome » CNC CalculatorsCALCULATOR Given valuesRadius + central angleRadius + arc lengthRadius + sagitta (segment height) Radius (in) Central angle […]Circular Segment CalculatorHome » CNC CalculatorsCALCULATOR Radius (in) Segment Angle (°) Segment Area— Segment Height (sagitta)— Area = 0.5 × R² × […]Cone Development CalculatorHome » CNC CalculatorsCALCULATOR Base Radius (in) Top Radius (in, 0 for full cone) Cone Height (in) Slant Height— Development […]Fillet Radius CalculatorHome » CNC CalculatorsCALCULATOR Fillet radius (in) Included angle between surfaces (°) —Tangent setback from corner —Fillet arc length —Chord […]Hole Pattern CalculatorHome » CNC CalculatorsCALCULATOR Pick Linear or Grid, enter the spacing and count, and this returns the X/Y coordinate of […]Hole Pattern GeneratorHome » CNC CalculatorsCALCULATOR Rows Columns X Spacing (in) Y Spacing (in) Start X (in) Start Y (in) Generates a […]Polygon CalculatorHome » CNC CalculatorsCALCULATOR Number of Sides Across Flats (in) Across Corners— Side Length— Interior Angle— For a regular polygon: […]Right Triangle CalculatorHome » CNC CalculatorsCALCULATOR Right triangle calculator finds the hypotenuse and angle from two known legs, a general-purpose geometry tool […]Sine Bar CalculatorHome » CNC CalculatorsCALCULATOR Sine bar calculator finds the gauge block stack height needed under one end of a sine […]Trigonometry CalculatorHome » CNC CalculatorsCALCULATOR Side A (in) Side B (in) Hypotenuse (Side C)— Angle Opposite A— Angle Opposite B— Right-triangle […]

📐 Milling 14

Axial Chip Thinning CalculatorHome » CNC CalculatorsCALCULATOR High feed mills cut with a shallow lead angle, so the chip the tooth removes is […]Ball Nose Effective Diameter and Feed CalculatorHome » CNC CalculatorsCALCULATOR Ball nose feed calculator accounts for a ball-nose end mill’s reduced effective diameter at shallow depths […]Corner Feed Reduction CalculatorHome » CNC CalculatorsCALCULATOR Cutting around a corner pulls the tool sideways, and the machine cannot apply infinite acceleration to […]End Mill Speed and Feed CalculatorHome » CNC CalculatorsCALCULATOR End mill speed and feed calculator converts cutter diameter, target surface speed, flute count, and chip […]Face Mill Speed and Feed CalculatorHome » CNC CalculatorsCALCULATOR Face mill speed and feed calculator converts cutter diameter, target surface speed, insert count, and feed […]Helical Interpolation CalculatorHome » CNC CalculatorsCALCULATOR When boring a hole larger than the tool by helical interpolation, the tool center follows a […]Keyway Dimension CalculatorHome » CNC CalculatorsCALCULATOR Looks up standard square/parallel key width and height for a given shaft diameter (ANSI inch square […]Pocket Milling Time CalculatorHome » CNC CalculatorsCALCULATOR Pocket length (in) Pocket width (in) Pocket depth (in) Tool diameter (in) Stepover (% of diameter) […]Radial Chip Thinning CalculatorHome » CNC CalculatorsCALCULATOR Tool diameter (in) Radial engagement / depth of cut (in) Desired chip thickness per tooth (in) […]Ramp Angle CalculatorHome » CNC CalculatorsCALCULATOR Ramp angle calculator finds the ramp length and toolpath distance needed to reach a target depth […]Slotting Feed CalculatorHome » CNC CalculatorsCALCULATOR Full-width slots (cutting at 100% of tool diameter) load every tooth more than a normal side-milling […]Stepdown (Axial DOC) CalculatorHome » CNC CalculatorsCALCULATOR Tool diameter (in) Flute length / length of cut available (in) StrategyRoughing — conservative (1.0x D)Roughing […]Stepover (Scallop Height) CalculatorHome » CNC CalculatorsCALCULATOR Stepover calculator finds the maximum lateral step distance for a ball-nose end mill that keeps scallops […]Surface Finish CalculatorHome » CNC CalculatorsCALCULATOR Estimate the theoretical surface finish a cut will leave. Turning finish comes from the feed and […]

📐 Drilling 12

Counterbore & Countersink CalculatorHome » CNC CalculatorsCALCULATOR Two calculators in one: countersink depth for flat-head screws, and counterbore diameter/depth for socket-head cap screws. […]Deep Hole Drilling CalculatorHome » CNC CalculatorsCALCULATORDeep-hole drilling calculator flags when a hole’s depth-to-diameter ratio requires peck-drilling technique, and works out the peck […]Drill Breakthrough CalculatorHome » CNC CalculatorsCALCULATORDrill breakthrough calculator finds the extra depth allowance needed for a drill’s conical point to fully break […]Drill Cycle Time CalculatorHome » CNC CalculatorsCALCULATOR Hole depth (in) Drill point allowance (in) Feed (in/rev) Spindle speed (RPM) Number of holes Peck […]Drill Feed CalculatorHome » CNC CalculatorsCALCULATORDrill feed rate converts spindle RPM and the recommended feed per revolution for a given drill diameter […]Drill Point Depth CalculatorHome » CNC CalculatorsCALCULATOR A drill bit’s tip is conical, so the hole must go deeper than the flat-bottom depth […]Drill RPM CalculatorHome » CNC CalculatorsCALCULATORDrill RPM converts a target cutting speed (SFM) and drill diameter into the spindle speed that keeps […]Drill Speed and Feed CalculatorHome » CNC CalculatorsCALCULATOR Drill speed and feed calculator converts drill diameter, target surface speed, and feed per revolution into […]Hole Depth-to-Diameter Ratio CalculatorHome » CNC CalculatorsCALCULATOR Check how deep a hole is relative to its diameter, the single biggest factor in whether […]Peck Drilling CalculatorHome » CNC CalculatorsCALCULATOR Peck drilling calculator finds the number of peck cycles and final peck depth needed to drill […]Spot Drill Depth CalculatorHome » CNC CalculatorsCALCULATORSpot drill depth calculates how deep to plunge a spotting or center drill to create a conical […]Through-Hole Drill Depth CalculatorHome » CNC CalculatorsCALCULATORThrough-hole drill depth calculates the total programmed drilling depth needed to fully break through a given material […]

📐 Tapping & Threading 12

Helical Thread Milling CalculatorHome » CNC CalculatorsCALCULATOR Hole Diameter (in) Thread Mill Diameter (in) Feed per Tooth (in) Number of Flutes Spindle Speed […]Metric Thread CalculatorHome » CNC CalculatorsCALCULATORMetric thread calculator finds tap drill, pitch diameter, and minor diameter for a standard metric ISO thread […]Rigid Tapping Feed CalculatorHome » CNC CalculatorsCALCULATOR Spindle Speed (RPM) Threads per Inch (TPI) Tapping Feed Rate (IPM)— Rigid Tapping Feed Rate = […]Single-Point Threading CalculatorHome » CNC CalculatorsCALCULATOR Threads per Inch (TPI) Number of Passes Total Thread Depth (60°)— Infeed per Pass— Thread Depth […]Tap Drill Size CalculatorHome » CNC CalculatorsCALCULATOR Thread systemInch (UN, specify TPI)Metric (specify pitch in mm) Major diameter Threads per inch (TPI) Pitch […]Tapping Speed CalculatorHome » CNC CalculatorsCALCULATOR Get spindle speed and feed rate for rigid tapping from tap diameter, threads per inch, and […]Thread CalculatorHome » CNC CalculatorsCALCULATOR Pick Metric or Unified, enter the major diameter and pitch (or threads per inch), and this […]Thread Depth CalculatorHome » CNC CalculatorsCALCULATOR Work out the key depths for tapping a thread: the height of one thread, how much […]Thread Engagement Length CalculatorHome » CNC CalculatorsCALCULATOR Estimate the minimum thread engagement length needed so the screw fails before the threads strip, based […]Thread Milling CalculatorHome » CNC CalculatorsCALCULATOR Get spindle speed and Z feed rate for cutting a thread with a thread mill helical […]Thread Percentage CalculatorHome » CNC CalculatorsCALCULATOR Nominal Major Diameter (in) Theoretical Minor Diameter (in) Actual Tap Drill Used (in) Thread Percentage— Thread […]Unified Thread CalculatorHome » CNC CalculatorsCALCULATORUnified thread calculator finds tap drill, pitch diameter, and minor diameter for a standard UN/UNC/UNF thread from […]

📐 Core CNC 11

Chip Load Calculator (Feed per Tooth)Home » CNC CalculatorsCALCULATOR Chip load calculator back-solves feed per tooth from a known feed rate, spindle RPM, and number […]Circular Interpolation CalculatorHome » CNC CalculatorsCALCULATOR Find the I and J offsets (arc center, relative to the start point) for a G02 […]Cutting Time CalculatorHome » CNC CalculatorsCALCULATOR Cutting time estimates how long a straight milling pass takes from cut length, feed rate, and […]Cycle Time CalculatorHome » CNC CalculatorsCALCULATOR Enter each cutting operation’s path length and feed rate, plus setup, tool-change, and rapid time, and […]Feed per Revolution CalculatorHome » CNC CalculatorsCALCULATORFeed per revolution converts spindle RPM and a chosen feed-per-rev value into the linear feed rate (IPM) […]Feed Rate Calculator (IPM)Home » CNC CalculatorsCALCULATOR Feed rate calculator converts spindle RPM, chip load per tooth, and number of flutes into the […]Material Removal Rate (MRR) CalculatorHome » CNC CalculatorsCALCULATOR Material removal rate (MRR) calculator estimates how much material volume is being removed per minute from […]Speeds and Feeds OptimizerHome » CNC CalculatorsCALCULATOR Pick your material, tool, and cutter size and this optimizer returns a complete starting point — […]Spindle Power & Torque CalculatorHome » CNC CalculatorsCALCULATOR Estimates the spindle power and torque required for a milling or turning cut, based on material […]Spindle RPM CalculatorHome » CNC CalculatorsCALCULATOR Spindle RPM calculator converts a target cutting speed (SFM) and tool or workpiece diameter into the […]Surface Feet Per Minute (SFM) CalculatorHome » CNC CalculatorsCALCULATOR Find cutting speed (surface feet per minute) from tool diameter and spindle RPM, the core number […]

📐 CNC Setup 11

Coordinate Rotation CalculatorHome » CNC CalculatorsCALCULATOR X Coordinate (in) Y Coordinate (in) Rotation Angle (°) New X— New Y— X’ = X·cosθ […]Edge Finder Offset CalculatorHome » CNC CalculatorsCALCULATOR Find the work coordinate offset to add when touching off an edge with a probe or […]Fixture Offset CalculatorHome » CNC CalculatorsCALCULATOR Machine Home to Fixture Datum (in) Fixture Datum to Part Zero (in) Fixture Offset (Work Coordinate)— […]ISO Hole/Shaft Fit & Tolerance CalculatorHome » CNC CalculatorsCALCULATOR Computes the actual hole and shaft size limits (in mm) for the five most common ISO […]Parallels / Stack Height CalculatorHome » CNC CalculatorsCALCULATOR Vise jaw height (in) Parallel height (in) Stock / part height (in) Min stock-above-jaw clearance needed […]Polar Coordinate CalculatorHome » CNC CalculatorsCALCULATOR X Coordinate (in) Y Coordinate (in) Radius— Angle— Radius = √(X² + Y²). Angle = atan2(Y, […]Probe Calibration CalculatorHome » CNC CalculatorsCALCULATOR Known/Master Diameter (in) Probe-Measured Diameter (in) Probe Error— Calibration Tip Offset (radius)— Probe Error = Measured […]Tool Length Offset CalculatorHome » CNC CalculatorsCALCULATOR Reference Tool Length (in) Current Tool Length (in) Tool Length Offset— Tool Length Offset = Reference […]Vise Clamping Pressure CalculatorHome » CNC CalculatorsCALCULATOR Check the actual clamping pressure on a part from a vise or clamp, so soft or […]Work Coordinate CalculatorHome » CNC CalculatorsCALCULATOR Machine X Position (in) Machine Y Position (in) Work Offset X (in) Work Offset Y (in) […]Workholding Clamping Force CalculatorHome » CNC CalculatorsCALCULATOR Cutting force (lbf) Friction coefficient (part-to-fixture) Safety factor Number of clamping points —Force per clamp —Total […]

📐 Tooling 10

Cutter Engagement CalculatorHome » CNC CalculatorsCALCULATOR Tool Diameter (in) Radial Width of Cut (in) Radial Engagement— Engagement Angle— Engagement % = WOC […]Maximum DOC CalculatorHome » CNC CalculatorsCALCULATOR Usable Flute Length (in) Tool Diameter (in) Max Axial DOC (Flute-Limited)— Max Recommended Radial DOC— Axial […]Runout Effect on Chip Load CalculatorHome » CNC CalculatorsCALCULATOR Tool runout means one flute does almost all the cutting while the others barely engage. This […]Tool Balance RPM CalculatorHome » CNC CalculatorsCALCULATOR Operating Spindle Speed (RPM) Tool/Holder Balance Grade (G) Max Recommended RPM for Grade— Status— Operating RPM […]Tool Cost per Edge CalculatorHome » CNC CalculatorsCALCULATORTool cost per edge estimates the true cost of each cutting edge from insert price, edges per […]Tool Deflection CalculatorHome » CNC CalculatorsCALCULATOR Tool diameter (in) Stickout length (in) Cutting force (lbf) Tool materialCarbide (E = 88 Msi)HSS (E […]Tool Life EstimatorHome » CNC CalculatorsCALCULATOR Reference preset (optional, fills C and n) — Manual entry —HSS tool, turning mild steel (C≈200, […]Tool Overhang Ratio CalculatorHome » CNC CalculatorsCALCULATOR Tool overhang ratio calculator estimates relative deflection from a tool’s stickout-to-diameter ratio, using a 3:1 ratio […]Tool Stickout CalculatorHome » CNC CalculatorsCALCULATOR Tool Stickout Length (in) Tool Shank Diameter (in) Length-to-Diameter Ratio— Relative Deflection Factor— High L:D ratio […]Toolholder Reach CalculatorHome » CNC CalculatorsCALCULATOR Pocket / Feature Depth (in) Holder Clamping Length (in) Clearance Margin (in) Required Toolholder Reach— Required […]

💰 Machining Cost 8

📐 Manufacturing & Production 8

📐 4th & 5th Axis 7

Scroll to Top

The calculators and tools on Formula Factory are provided for general guidance and informational purposes only. Results are estimates based on standard formulas and the values you enter — they do not constitute professional engineering, electrical, or architectural advice. Always verify calculations with a qualified professional before making decisions for any safety-critical, code-compliance, or commercial application. Formula Factory makes no representations or warranties as to the accuracy or completeness of any result, and accepts no liability for errors, omissions, or any outcomes arising from reliance on this information.