💥 Car Crash Calculator
Estimate the average force and g-force of a vehicle collision from speed, mass, and stopping distance.
Estimating Crash Forces
This calculator estimates the average force involved in a collision using the work-energy relationship: the vehicle’s kinetic energy is absorbed over the stopping (crumple) distance. First the average deceleration is found from a = v2 / (2d), then the average force from Newton’s second law, F = ma.
The g-force is simply the deceleration divided by standard gravity (9.81 m/s²), a common way to compare impact severity. A longer crumple/stopping distance spreads the same energy over more distance, sharply lowering both force and g-force.
This is a simplified average-force model for general educational purposes. Real crashes involve non-uniform deceleration, structural deformation, and restraint systems, so it should not be used to assess actual injury risk or vehicle safety.