Blast Timing Delay Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserIntermediate
Enter Values
Enter your values and press Calculate to see results.
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.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.