# Atmosphere (standard) conversions

The atmosphere (standard) conversion selector above selects the pressure/stress measurement unit to convert to starting from atmospheres (standard) (atm). To make a conversion starting from a unit of pressure other than atmosphere (standard), simply click on the "Reset" button.

## About atmosphere (standard)

The standard **atmosphere** is a unit of pressure equal to 101,325 pascals (1 atm = 101,325 Pa), the SI derived unit of pressure.

The standard atmosphere (atm) is also equal to 1,013.25 hectopascals (hPa), or 101.325 kilopascals (kPa), or about 1.033227453 technical atmosphere (at), or 1.01325 bars (bar), or 760 millimeters of mercury at 0 °C (mmHg), or 406.782 inches of water at 4 °C (inH_{2}O), or 14.69595 pounds per square inch (psi), or 2,116.21662 pounds per square foot (psf) or 760 torr (Torr).

The standard atmosphere is equal to 1,013,250 dynes per square centimeter (1 atm = 1,013,250 dyn/cm^{2}). The dyne (dyn) is a unit of force in the centimetre-gram-second (CGS) system of units while the square centimeter (cm^{2}) is a unit of area in the SI.

In chemistry, the International Union of Pure and Applied Chemistry (IUPAC) recommends that the physical properties of substances be specified at "the standard pressure" rather than at "one standard atmosphere". In this regard "the standard pressure" is defined as exactly 100 kilopascals (or 1 bar).

The standard atmosphere is used in science, engineering, and the aerospace and petroleum industries.

Symbol: atm

Plural: atmospheres (standard)