Find how fast sound travels. This free speed of sound calculator computes the speed in air by temperature (°C or °F), or in water, glass and steel, with results in m/s, km/h, mph and Mach 1.
In air, the speed of sound rises with temperature – about 0.6 m/s for every 1 C. Pick another medium to use a typical fixed value (sound travels much faster in liquids and solids).
Using a typical value for this medium. The exact speed depends on temperature, pressure, salinity and composition.
For air, this uses v = 331.3 x sqrt(1 + T/273.15) with T in C – the standard dry-air approximation. At 0 C sound travels about 331 m/s; at 20 C about 343 m/s.
How the Speed of Sound Calculator Works
This tool finds how fast sound travels through a chosen medium — using a temperature-based formula for air, and typical fixed values for liquids and solids like water, steel, and glass.
Formula: For air, v = 331.3 × √(1 + T ÷ 273.15), where T is the air temperature in degrees Celsius (this is the standard dry-air approximation). For other media, the calculator uses a typical fixed speed instead: water ≈1481 m/s, seawater ≈1500 m/s, steel ≈5960 m/s, aluminium ≈6420 m/s, glass ≈3240 m/s.
- Material — the medium sound travels through: air (by temperature), water, seawater, steel, aluminium, glass, or a fixed 20°C air value
- Air temperature — only used when Air is selected; enter in °C or °F using the unit toggle
Example Scenarios
| Medium | Temperature | Speed of Sound |
|---|---|---|
| Air | 0°C | 331.3 m/s |
| Air | 20°C | ≈343.2 m/s |
| Air | 30°C | ≈349.0 m/s |
| Air | -10°C | ≈325.2 m/s |
| Water (fresh) | n/a (fixed value) | 1,481 m/s |
| Steel | n/a (fixed value) | 5,960 m/s |
Speed of Sound Calculator FAQ
Why does the speed of sound depend on air temperature?
Sound travels as a pressure wave carried by moving air molecules, and warmer air molecules move faster, transmitting the wave more quickly. This calculator models that with v = 331.3 × √(1 + T/273.15), where T is in Celsius.What’s the speed of sound at 20°C?
Using this calculator’s air formula, sound travels at approximately 343.2 m/s at 20°C, which is close to the commonly cited “room temperature” value of 343 m/s.How much faster does sound travel through water or steel than air?
Much faster. This calculator uses fixed typical values of about 1,481 m/s for fresh water and 5,960 m/s for steel, versus roughly 343 m/s for air at 20°C — sound moves several times faster through denser, stiffer materials.What does the “Mach 1 equals” result mean?
It shows the current medium’s speed of sound restated as the reference speed for Mach 1, so you can see what speed an object would need to reach to be considered supersonic in that medium.Does this calculator account for humidity or air pressure?
No. It uses the standard dry-air temperature approximation (v = 331.3 × √(1 + T/273.15)), which doesn’t factor in humidity, altitude, or atmospheric pressure changes.Can I enter the temperature in Fahrenheit?
Yes. Use the °C / °F toggle next to the temperature field to switch units before entering your air temperature value.Related Calculators
Sound is a wave, so if you know a sound’s speed and frequency you can also find its wavelength with the wavelength & frequency calculator. Since temperature drives this calculation, it’s worth also checking how cold or hot air actually feels with the wind chill calculator or the heat index calculator.