Blast Timing Delay Calculator
Computes inter-hole and inter-row blast delays from millisecond-per-metre timing and pattern spacing.
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Minimum 0
Minimum 0
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter the spacing and burden.
- Optionally set the ms-per-metre rates.
- Press Calculate for the inter-hole and inter-row delays.
How it works
Guideline timing: inter-hole delay ≈ spacing × (3–7 ms/m); inter-row delay ≈ burden × (10–25 ms/m). Always follow the approved blast design.
Worked example
3.5 m spacing, 3 m burden. ≈ 11 ms between holes, ~36 ms between rows (at default rates).
Frequently asked questions
Why does timing matter?
Delays control fragmentation, muckpile shape, vibration and airblast by letting each hole break to a free face.
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Cite this tool
Zerdly. (2026). Blast Timing Delay Calculator. Retrieved from https://www.zerdly.com/tools/blast-timing-delay-calculator/
Tip: Enter any known values to calculate the remaining results.
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