At an altitude of about 16,000 feet, what is the atmospheric pressure in comparison to sea level?

At an altitude of about 16,000 feet, the atmospheric pressure is significantly lower than at sea level. As altitude increases, the weight of the air above decreases, leading to a reduction in atmospheric pressure. At sea level, standard atmospheric pressure is approximately 1013.25 hPa (hectopascals) or 29.92 inches of mercury (inHg).

As a rule of thumb, atmospheric pressure decreases by about 50% for every increase of approximately 18,000 feet in altitude. Therefore, at 16,000 feet, the pressure can be estimated to be around half of what it is at sea level. This decrease in pressure can have physiological effects, particularly in diving and high-altitude environments.

Understanding this concept is crucial for divers, especially when considering the implications of equalizing pressures and the potential for altitude-related issues during dives conducted at higher elevations.