how many torr in 1 atm

One standard atmosphere (atm) is exactly equivalent to 760 torr. The torr is a unit of pressure named after Evangelista Torricelli, the inventor of the barometer. By definition, one torr is equal to one millimeter of mercury (1 mmHg). The standard atmosphere, which is a unit of pressure often used as a reference point, is therefore defined as the pressure that supports a column of mercury 760 millimeters high. This conversion is a fundamental constant used across science and engineering in India and worldwide for measuring pressure.