# Speed of Sound Calculator: knots, mach, mph

Calculate the speed of sound in various units (Knots, Mach, MPH, km/h, m/s, ft/s) based on the air temperature. Enter your air temperature and select the temperature unit to find the speed of sound.

## Speed of Sound Calculator

### Speed of Sound

In the Earth’s atmosphere, the chief factor affecting the speed of sound is thetemperature.

**>>** Temperature Converter: Convert to/from °F, °C, K

The speed of sound refers to how fast sound waves travel through a medium such as air, water, or a solid. In the Earth’s atmosphere, the speed of sound is influenced by factors such as:

- Temperature (the main factor)
- Humidity
- Altitude/Pressure

The speed of sound in the atmosphere is calculated using the following formula:

V_sound = 643.855 x (T / 273.15)^{0.5}

Where:

**v_sound**is the speed of sound in knots.**T**is the air temperature in Kelvin.**643.855**is a constant used to calculate the speed of sound in knots.

**Note:** Mach 1 is defined as the speed of sound under standard atmospheric conditions, which are 288.15 Kelvin (15°C or 59°F). Under these conditions, the speed of sound is approximately 343 meters per second (m/s).