Acoustic Impedance Calculator

About this calculator

This calculator finds the characteristic acoustic impedance of a medium, Z = ρ × c — density multiplied by the speed of sound through that medium — expressed in rayls (kg/m²·s). It's a property of the material itself, describing how much it resists the passage of a sound wave.

Acoustic impedance governs what happens at the boundary between two media: the bigger the impedance mismatch, the more sound energy reflects rather than transmits across it, which is exactly why an ultrasound gel is used to bridge the impedance gap between air and skin, and why bone and soft tissue show up so differently on an ultrasound image. It's a core parameter in medical ultrasound, sonar, and architectural and materials acoustics wherever engineers need to predict reflection and transmission at an interface.