What is the standard atmospheric pressure at sea level?

The standard atmospheric pressure at sea level is defined as 1013.25 hPa or 1 atm (atmosphere). This value is an essential reference point in various scientific and engineering calculations, especially those related to gas laws, diving, and meteorology.

At sea level, the weight of the atmosphere above a unit area exerts a pressure of 1013.25 hPa. This standard pressure is universally recognized and serves as a baseline for measuring atmospheric pressure in other locations and under different conditions. Variations in atmospheric pressure can have significant implications for weather patterns, buoyancy in diving, and the behavior of gases in different environments.

Understanding this standard is crucial for divers, as changes in pressure during descent and ascent affect buoyancy and nitrogen absorption in the body. Recognizing that 1013.25 hPa corresponds to 1 atm helps divers calculate their diving profiles and manage the risks associated with pressure changes.