How do you calculate drilling cycle time?

Divide total drilled depth by the drilling feed rate for base time, then multiply by (1 + allowance%). A 48 in total depth at 16 in/min gives 3 min base; a 25% allowance gives an estimated 3.75 min.

Why is the drilling allowance higher than for milling?

Peck drilling retracts the drill repeatedly to break and clear chips, and each retract is non-cutting motion. Deep holes in gummy materials can need many pecks, so 20-30% allowance is common versus 10-15% for milling.

What is total drilled depth if I have many holes?

Add up the drilled depth of every hole in the pattern. Twelve holes each 4 inches deep total 48 inches, which is the figure you enter, not the depth of a single hole.

Does peck drilling always increase cycle time?

Yes, in raw time, because each retract is air movement. But it prevents chip packing, drill breakage, and scrapped parts, so the time penalty buys reliability on deep or sticky-chipping holes.

What is a good drilling feed rate to assume?

It depends on drill diameter and material, but use the effective feed your program achieves. For the estimate, 16 in/min is a reasonable mid-range value for moderate-diameter holes in aluminum or mild steel.

Drilling cycle time vs. tapping cycle time, what's different?

Tapping is feed-locked to thread pitch and reverses out, while drilling feed is set by chip load. Tapping usually carries a higher allowance for spindle reversal and synchronization, so the two need separate estimates.

CNC Machining calculator

Drilling Cycle Time Calculator

Drilling cycle time is the spindle-on time to produce a hole or set of holes, padded with an allowance for peck retracts, rapid plunges, and chip clearance moves. Process planners and CNC programmers use it to quote drilled parts, estimate how long a hole pattern adds to a routing, and decide whether peck drilling is worth the time penalty. Drilling allowances run higher than milling or turning because deep holes need frequent retracts to clear chips, and those air moves can rival the cutting time itself. On the floor, this is the number that tells you whether a 12-hole part is a 4-minute job or an 8-minute one.

What this calculator does

Estimate drilling cycle time from total drilled depth, feed rate, and allowance for pecking, retracts, spot drilling, or chip clearing.
estimating drilling cycle time for quoting, routing, capacity planning, or comparing alternate CNC programs
It divides total drilled depth by the drilling feed rate for base time, then multiplies by an allowance factor for peck retracts, rapid moves, and chip clearance.

Formula used

Base drilling cycle time = total drilled depth ÷ drilling feed rate
Estimated drilling cycle time = base time × allowance factor

Inputs explained

total drilled depth: Use the total distance actually traveled in the cutting or feed-controlled portion of the operation.
drilling feed rate: Use the programmed feed for the operation after any process derating or override assumptions.
peck, retract, and chip-clearance allowance: Add allowance for entry, exit, tool changes tied to the operation, chip clearing, positioning, and minor machine delays.

How to use the result

Use it when quoting or planning drilled features where you know the cumulative hole depth and feed but want a fast estimate including peck overhead.
It treats peck and chip-clearance time as a flat allowance, so it can misjudge very deep holes where retract count and dwell dominate and the real overhead is nonlinear.

Current U.S. benchmarks

The producer price index for steel mill products stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 17,154 machine shops establishments employing about 223,303 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate drilling cycle time? Divide total drilled depth by the drilling feed rate for base time, then multiply by (1 + allowance%). A 48 in total depth at 16 in/min gives 3 min base; a 25% allowance gives an estimated 3.75 min.
Why is the drilling allowance higher than for milling? Peck drilling retracts the drill repeatedly to break and clear chips, and each retract is non-cutting motion. Deep holes in gummy materials can need many pecks, so 20-30% allowance is common versus 10-15% for milling.
What is total drilled depth if I have many holes? Add up the drilled depth of every hole in the pattern. Twelve holes each 4 inches deep total 48 inches, which is the figure you enter, not the depth of a single hole.
Does peck drilling always increase cycle time? Yes, in raw time, because each retract is air movement. But it prevents chip packing, drill breakage, and scrapped parts, so the time penalty buys reliability on deep or sticky-chipping holes.
What is a good drilling feed rate to assume? It depends on drill diameter and material, but use the effective feed your program achieves. For the estimate, 16 in/min is a reasonable mid-range value for moderate-diameter holes in aluminum or mild steel.

Last reviewed 2026-05-12.