What is the sea level pressure in the ICAO standard atmosphere?

In the ICAO (International Civil Aviation Organization) standard atmosphere, the sea level pressure is defined as 29.92 inches of mercury (in Hg). This value serves as a reference point for calibrating altimeters and is critical for ensuring accurate altitude readings during flight operations. The standard atmosphere model is used globally for aviation and meteorological purposes, providing a consistent baseline for comparing atmospheric conditions.

The value of 29.92 in Hg corresponds to a pressure of 1013.25 hPa (hectopascals) or 1013.25 mbar, which is the metric equivalent commonly used in weather reporting and aviation. This standard simplifies communication, enhances safety, and aids in the planning and execution of flight operations, as pilots and air traffic controllers rely on this common reference for altitude and pressure measurements.

Understanding the standard atmospheric pressure not only helps pilots in calibrating their instruments but also assists them in making informed decisions about performance calculations at various altitudes.