Speed of Sound Calculator
The speed of sound depends on the medium through which it travels and the temperature. In air at 20°C, sound travels at approximately 343 m/s (1,235 km/h). This calculator lets you find the speed of sound in various media and convert between common units.
Sound is a mechanical wave that requires a medium to propagate. Its speed depends on the medium's density and elasticity. In general, sound travels fastest through solids (steel ≈ 5,960 m/s), slower through liquids (water ≈ 1,480 m/s), and slowest through gases (air ≈ 343 m/s at 20°C).
In air, the speed of sound increases with temperature according to the approximation v = 331.3 + 0.606T, where T is in degrees Celsius. This is because higher temperatures mean faster-moving air molecules, enabling quicker transmission of pressure waves. In helium, sound travels nearly three times faster than in air due to helium's much lower molecular mass.
Mach number expresses an object's speed relative to the local speed of sound. Mach 1 is the speed of sound; Mach 2 is twice the speed of sound. The sound barrier (the dramatic increase in aerodynamic drag near Mach 1) was first broken by Chuck Yeager in 1947. Understanding the speed of sound is fundamental in acoustics, aeronautics, and seismology.