How to estimate laser cutting time
Laser cutting time is more than length divided by speed. Pierces, corner slowdown, and idle travel between contours add real minutes. This guide walks through the pieces, works a round-number example labelled as synthetic, and explains how AllTerra Calculator builds machine time from the nest.
The main time building blocks
A practical shop estimate usually combines:
- Cut time — cut length ÷ cut speed (with optional complexity factor).
- Pierce time — pierce count × pierce time per start.
- Corner slowdown — extra time near sharp corners when the mode slows the head.
- Idle / rapid travel — moves between contours with the beam off.
Speeds and pierce times come from your cutting mode for material and thickness. Geometry (length, pierces, corners, idle path) comes from the nested layout. Without both, the clock is fiction.
Worked synthetic example (round numbers)
Example only — not a customer job and not a default AllTerra rate card. Suppose a nest reports 12 000 mm of cut length, 40 pierces, and 3 000 mm of idle travel. Shop mode values for this example: cut speed 6 000 mm/min, pierce time 0.5 s, rapid speed 30 000 mm/min. Ignore corners for the first pass.
| Input (example) | Value |
|---|---|
| Cut length | 12 000 mm |
| Cut speed | 6 000 mm/min |
| Pierces | 40 |
| Pierce time | 0.5 s each |
| Idle travel | 3 000 mm |
| Rapid speed | 30 000 mm/min |
Then:
- Base cut hours = (12 000 ÷ 6 000) ÷ 60 = 0.0333 h ≈ 2.0 min.
- Pierce hours = 40 × 0.5 ÷ 3600 ≈ 0.0056 h ≈ 0.33 min.
- Idle hours = 3 000 ÷ 30 000 = 0.1 min of rapid time (same formula family as cut length/speed).
- Machine time ≈ cut (+ pierces already in cut-time bucket in AllTerra) + idle; gas is not charged on idle because the beam and assist gas are off between cuts.
Label: synthetic teaching example with round numbers. Replace every figure with your nest metrics and your cutting-mode rows.
If the same parts are nested more loosely, idle travel often grows even when cut length stays similar. That is why machine time depends on the nest, not only on the DXF perimeter.
Corner slowdown
On sharp corners many controllers ease speed over a short zone. Extra time is roughly: for each corner, time to traverse the corner zone at reduced speed minus time for the same zone at full speed. Modes store a corner slowdown factor and corner zone length.
Ornamental parts with many corners accumulate seconds. Thick plate with aggressive slowdown does too. Flat rectangular nests with few corners may barely notice it.
In AllTerra Calculator
Machine time is shared by both live pricing models (Business plan and Hourly rate). The economic engine builds cut time from nested cut length and the cutting-mode speed, multiplies by a complexity factor when set, adds corner extra when corners and slowdown apply, adds pierce_count × pierce_time, then adds idle hours from rapid travel length and rapid speed.
Cut length and pierces come from the nest / order geometry. Idle length is computed from the final nest path (including post-steps such as edge-as-part handling and micro-joints where used). Pierces include outer contours and holes.
Gas cost in Business plan stays tied to cut time (and per-pierce gas where configured), not to idle moves. Labour and several equipment lines can follow full machine time including idle.
Cutting-mode fields you maintain include cut speed (mm/min), pierce time (s), corner slowdown factor, corner zone length, kerf, gas, and related power settings. Empty shop rates do not become invented industry averages.
How shops use the estimate
Calibrate modes on a job you already timed on the floor. If pierce time is optimistic, small parts will be systematically cheap. If rapid speed is optimistic, sparse nests will look too fast.
Repositioning a long sheet that does not fit the machine bed can add handling minutes on top of beam time — AllTerra can account for sheet reposition norms when that feature applies. Do not confuse beam-on time with total calendar time through the cell.
For formula detail in product language, see how pricing works and the cost calculator page. For packing that feeds length and idle, see the nesting engine guide and the guides index.
Small parts amplify pierce share. A washer nest can spend more time piercing than travelling along short outer edges. Thick plate amplifies pierce seconds and sometimes corner slowdown. Check both before you blame nesting for a “slow” quote.
Idle travel is the silent line on sparse nests: few long contours far apart look fine in cut length but burn clock on rapids. If two nests share cut length within a few percent yet differ in machine time, inspect idle length in the calculation result.
When you change Shared cut, cut length and pierce count may fall while idle path shape changes. Re-read machine time after the toggle; do not assume every metre of cut saved is a minute saved under the beam schedule.
Document the cutting-mode row used on the quote (material, thickness, speed, pierce time). Without that, a later dispute about “the calculator was slow” cannot be replayed. AllTerra stores modes in company settings so the next order reuses the same shop facts.