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MachiningCalc / Drill Speed & Feed Calculator

Drilling · speed and feed

Drill Speed & Feed Calculator

Calculate drill RPM and linear feed from diameter, cutting speed and feed per revolution. The calculator keeps drilling feed math separate from milling chip-load math.

Instant resultNo signupFormula shownReviewed Aug 2026
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Calculator

Enter the known values. Results update automatically.

Spindle speed—
Feed rate—
Surface speed—
Feed / revolution—

Use tooling manufacturer data and stay within machine, tool and workholding limits. Calculated values are not a substitute for validated process parameters.

Immediate resultUpdates as inputs change
US machining unitsSFM, RPM, IPR, IPM
Formula visibleNo black-box output
Focused intentOne machining job per URL

Calculation method

Calculation

RPM = SFM × 12 ÷ (π × Drill Diameter)IPM = RPM × Feed per Revolution

Use values in the units shown by the calculator. Inputs must be positive and physically meaningful.

How to calculate drill speed and feed

Start with drill-specific cutting speed and feed per revolution. The calculator converts SFM and diameter into RPM, then multiplies RPM by IPR to return the linear feed in IPM.

Effective diameter and drilling speed

Surface speed varies across a drill from the center to the outer diameter. Shop calculations conventionally use the drill diameter for the peripheral cutting-speed relationship. Specialized geometries may require manufacturer-specific guidance.

Drilling vs milling feeds

OperationCommon feed inputLinear feed
DrillingIPR / feed per revolutionRPM × IPR
End millingIPT / chip load per toothRPM × teeth × IPT

How to interpret the result

If the calculated RPM exceeds the machine or holder limit, cap RPM and recompute the achieved SFM. If you cap RPM but keep the same IPR, recalculate IPM from the lower spindle speed.

Factors that affect drilling feeds

Hole depth, coolant delivery, chip evacuation, drill point geometry, runout, material hardness and peck strategy can all change the usable feed. Deep-hole drilling deserves tool-specific data rather than a simple shallow-hole assumption.

Methodology, standards and validation

MachiningCalc separates deterministic math from cutting-data recommendations. The calculator performs the geometry and unit relationships; the correct starting cutting data still depends on the tool, work material, coating, machine and setup.

Sources and methodological references

Frequently asked questions

Drill Speed & Feed Calculator: common questions

How do you calculate speeds and feeds for a drill?

Calculate RPM from SFM and drill diameter, then multiply RPM by feed per revolution to get IPM.

What is the formula for drilling speed?

For inch units, RPM = SFM × 12 ÷ (π × drill diameter).

What feed should I use for a drill?

Use the drill manufacturer's feed-per-revolution data for the exact diameter, geometry and work material rather than a universal value.

Why is drilling speed math different from end milling?

The surface-speed formula is the same, but drilling feed is commonly specified per revolution while milling commonly uses chip load per tooth.

What is effective diameter?

It is the diameter at which the cutting edge is actually generating surface speed. For a conventional drill calculation, use the drill's cutting diameter.