A drill speed and feed calculator should answer two immediate programming questions: what spindle speed corresponds to the selected cutting speed, and what linear feed corresponds to the feed per revolution? This page keeps those calculations separate so a drill chart can be translated into CNC values without hiding the unit relationships.
Use the spindle-speed tool for the rotational side of the job and the feed-per-rev tool for the axial feed side. The result is most useful when paired with the exact drill data for the material, drill type, coolant strategy and hole depth. Solid carbide, carbide-tipped, indexable and HSS drills can require very different starting conditions even when the diameter is identical.
Start with the basic calculation, then go deeper
Run the smallest calculation that matches the job. Use the advanced version when additional process or machine variables need to be checked.
Quick Drilling Calculator
Run the common calculation for this machining task.
Spindle Speed
Enter the values you know. The result is calculated in your browser.
Calculation only. Verify toolmaker data, material grade, engagement, machine limits, workholding and actual cutting conditions before production.
Advanced Drilling Calculation
Add the main process variables and machine checks for a fuller calculation.
Feed Per Rev
Enter the values you know. The result is calculated in your browser.
Calculation only. Verify toolmaker data, material grade, engagement, machine limits, workholding and actual cutting conditions before production.
What this drill speed and feed calculator calculates
Enter drill diameter, cutting speed, RPM and programmed feed. Then document the hole depth, drill type, point geometry, coating and workpiece material. For deep drilling, note whether through-tool coolant is available and whether a peck cycle is recommended by the toolmaker. Those details can change the practical cutting condition without changing the underlying formulas.
Formulas and unit handling
Drilling RPM is RPM = (1000 × Vc) ÷ (π × D) in metric or RPM = (12 × SFM) ÷ (π × D) in imperial. Feed is F = RPM × f, where f is feed per revolution. The same formula works for checking a programmed drilling feed as well as converting a catalog value into the linear feed expected by the CNC.
Drill RPM = (1000 × Vc) ÷ (π × D).Use the source unit shown in your tooling reference before converting.Drill RPM = (12 × SFM) ÷ (π × D).Use the source unit shown in your tooling reference before converting.Feed = RPM × feed per revolution.Use the source unit shown in your tooling reference before converting.Feed per revolution = feed ÷ RPM.Use the source unit shown in your tooling reference before converting.Step-by-step workflow
Technical context for this search
Drill and drilling are closely related search intents, but this page is intentionally focused on the practical RPM and feed-per-revolution relationship for a drill. Use the tool diameter and cutting-speed input to establish spindle RPM, then express the programmed linear feed as feed per revolution. That is the easiest way to compare a CNC program with a conventional drill manufacturer table.
Drill diameter is the biggest driver of RPM because the formula divides the selected cutting speed by the rotating circumference. Changing the drill from 10 mm to 8 mm while holding surface speed constant should therefore increase RPM. If a program keeps the old RPM without rechecking surface speed, the actual cutting condition has changed even when the feed value remains unchanged.
Hole depth and chip evacuation are process limits that sit beside the arithmetic. A short through-hole, a deep blind hole and an interrupted entry can require different cycle strategies or coolant conditions. The calculator should not be presented as a peck-cycle generator or a guarantee of tool life. It is a transparent layer for turning a known drilling condition into machine values.
For a first article, inspect the actual hole diameter, wall quality, chip shape and spindle load. If the drill walks at entry, look at workpiece location and drill condition before changing feed. If chips pack, inspect coolant and cycle behavior. Recording those observations with RPM and feed makes later adjustments more deliberate.
Calculation audit checklist
| Check | What to verify |
|---|---|
| Operation check | Confirm that the job is actually drilling before entering values. The calculator pair on this page was selected for the drill speed and feed calculator search intent, so switching to another operation may require a different feed convention. |
| Source check | Use the exact tooling or process reference behind drill speed and feed calculator. Record the tool or process identifier, material and source units before converting anything; the site calculates from supplied values rather than selecting proprietary cutting data. |
| Input check | Verify the primary inputs used by the spindle-speed and feed-per-rev calculators. A field can be numerically valid while still being the wrong variable for the operation, especially when moving between chip load, feed/rev, feed rate and surface speed. |
| Unit check | Keep metric and imperial values separated through the calculation. Recheck diameter, cutting speed and feed units on the Drill Speed and Feed Calculator page before accepting the result, and only round after the relationship has been verified. |
| Machine check | Compare the theoretical output with machine spindle, feed, travel and process limits. A calculated value is not a machine capability statement, and a controller limit can make the effective cutting condition different from the selected target. |
| Tool/setup check | Review tool condition, runout, overhang, workholding and coolant or lubrication where relevant to drilling. These variables are outside the arithmetic model but can dominate the actual cutting result. |
| First-cut check | Treat the first part or first hole as a validation event. Record chips, sound, load, finish and dimensional result alongside the calculated RPM/feed so later changes can be traced to evidence rather than memory. |
| Recordkeeping check | For repeat work, save the source reference, selected inputs, calculated values and final programmed values together. The Drill Speed and Feed Calculator calculation then becomes a reproducible setup record instead of a one-time online number. |
Worked example
A 6 mm drill at 100 m/min corresponds to about 5,305 RPM. At 0.08 mm/rev, linear feed is about 424 mm/min. A production programmer would still cross-check those values against the drill manufacturer’s recommended range and the hole-depth limit before running the cycle.
Practical setup checks
Drilling produces chips inside a confined channel, so chip evacuation is central. Check whether the drill is intended for through-coolant or external coolant, and whether the hole depth changes the recommended condition. If the tool is entering an interrupted surface or a cross hole, the standard numbers may not directly transfer.
Common mistakes
- Using a milling feed-per-tooth formula for a conventional drill.
- Forgetting to recalculate RPM after changing drill diameter.
- Ignoring hole depth and chip evacuation.
- Assuming a peck cycle solves every drilling problem.
- Skipping a first-hole measurement.
Troubleshooting the calculated condition
For hole-size issues, inspect runout and entry stability. For chip problems, check coolant, flute condition and cycle strategy. For overheating, verify the cutting speed against the exact drill grade and material. For excessive load, inspect feed, drill condition and hole preparation before assuming the spindle speed is the cause.
How to cross-check tool data
Treat the drill manufacturer’s exact product data as the primary cutting-data source. This calculator is the numerical layer for converting and auditing that data.
Frequently asked questions
What is the basic drill feed formula?
Feed rate equals RPM multiplied by feed per revolution.
Why do small drills need high RPM?
The RPM formula divides by diameter, so a smaller drill needs more revolutions to maintain the same surface speed.
Does drill speed depend on hole depth?
The formula itself does not include depth, but the manufacturer’s recommended operating range can change with hole depth and coolant strategy.
Can this calculator choose a peck cycle?
No. Cycle strategy depends on the drill, hole depth, machine control and chip evacuation requirements.
This page calculates relationships from the values supplied by the user. It does not inspect the machine, tool condition, workholding or material state. Verify production cutting values against the exact tooling reference and the actual setup before running the cut.