PPolySim OS

Blast Standoff / Overpressure

How far is far enough? Set the charge size and see the overpressure at a given distance, plus the standoff where blast pressure falls to the window-breakage threshold.

Blast Standoff / OverpressureLive
At 30 m from 10 kg
7.8 kPa
Window breakage

Controls

Presets

83 kPa — Severe structural / lethal
35 kPa — Serious injury, wall collapse
14 kPa — Eardrum rupture risk
3.5 kPa — Window breakage

Peak incident overpressure follows Hopkinson-Cranz cube-root scaling: the scaled distance Z = R/W^(1/3) sets the blast pressure. Rings show injury and damage thresholds. Screening estimate for standoff planning only — consult EOD and published safe-distance tables on scene.

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Data Inspector

Overpressure7.8 kPa
In psi1.13
Window-safe standoff65 m

Governing equation

Reading this result: At 30 m from 10 kg the scaled distance is Z ≈ 13.9 m/kg^1/3, giving about 8 kPa (window breakage) — since Z = R/W^(1/3), the same pressure ring scales with the cube root of charge, so 8× the explosive only doubles every safe radius.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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How it works

Blast overpressure scales by the Hopkinson-Cranz cube-root law: the scaled distance Z = R/W^(1/3) determines peak pressure, so doubling the charge only extends a given pressure ring by about 26 percent. Colored rings mark injury and damage thresholds. This is a screening estimate for standoff planning and training — always defer to EOD technicians and official safe-distance tables on an actual device.

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Frequently asked questions

Is this blast standoff distance calculator tool really free?
Yes. Blast Standoff / Overpressure runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
Do I need to install anything?
No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
Can I save or share my simulation?
Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.
How accurate are the results?
The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.