Blast Radius Calculator

Calculate safe distances from explosive detonations using Hopkinson-Cranz scaling law

SAFETY WARNING

This calculator provides indicative distances only. Areas outside the calculated radius remain UNSAFE. Extreme caution is advised. This tool is for educational purposes only.

Calculate Blast Radius

Total mass of the explosive material (TNT equivalent)

Type of explosive configuration

Blast Radius Results

0.0
Meters (m)
0.0
Feet (ft)
0.0
Yards (yd)
0.000
Kilometers (km)

Formula used: D = 130 × W^(1/3)

Explosive mass: 0.000 kg TNT equivalent

Scaled distance: 0.00 m/kg^(1/3)

Safety Analysis

Example Calculation

Example: 0.5 kg bare exposed TNT

Calculation: D = 130 × (0.5)^(1/3) = 130 × 0.794 = 103.2 m

Result: Safe distance approximately 103 meters from detonation point

Hopkinson-Cranz Scaling Law

Bare Explosives

D = 130 × W^(1/3)

Direct exposure formula

Fragmented (Public)

D = 634 × W^(1/6)

Public access areas

Fragmented (Restricted)

D = 444 × W^(1/6)

Restricted access areas

Safety Guidelines

⚠️

Calculated distance is minimum safe distance

🚨

Areas outside radius remain unsafe

📏

Distance assumes no fragment protection

🎯

For educational purposes only

Always maintain maximum distance possible

Understanding Blast Radius and Explosions

What is Blast Radius?

Blast radius is the distance from an explosion beyond which the effects are significantly reduced. It's calculated using the Hopkinson-Cranz scaling law, which relates explosive weight to safe distances.

Blast Wave Physics

  • Shock wave originates from detonation point
  • Pressure wave travels spherically outward
  • Intensity decreases with distance cubed
  • Fragment dispersion follows ballistic trajectories

Hopkinson-Cranz Law

W₁/W₂ = (R₁/R₂)³

  • W: Mass of explosive (TNT equivalent)
  • R: Distance from explosion center
  • Z: Scaled distance = R/W^(1/3)

Warning: These calculations provide minimum safe distances. Actual safety requires much greater distances and professional assessment.