Convert Hectopascal to Attopascal (hPa to Attopascal)

Hectopascal (hPa) and Attopascal (Attopascal) are both units of pressure. With the conversion form below, you can effortlessly and accurately convert hectopascal to attopascal. This free online calculator tool makes it simple and easy to perform the conversion from hPa unit to the Attopascal unit.

Pressure is the force applied perpendicular to a surface per unit area: P = F / A. The SI unit is the pascal (Pa), equal to one newton per square metre (1 Pa = 1 N/m²). Practical applications use larger units: the bar (1 bar = 100,000 Pa, close to standard atmospheric pressure), atmosphere (atm) (1 atm = 101,325 Pa), and psi (pounds per square inch, used in the US for tire and gas pressures). Blood pressure is measured in mmHg (millimetres of mercury), also called torr.

The hectopascal (symbol: hPa) is an SI-derived unit of pressure equal to 100 pascals. It is one of the most widely used pressure units in meteorology and weather forecasting, where atmospheric pressure is commonly reported in hectopascals. The hectopascal uses the SI prefix hecto, representing a factor of one hundred.

One hectopascal is equal to 100 pascals, 0.1 kilopascal, 0.001 bar, 1 millibar, and 0.000986923 standard atmosphere. The hectopascal is the international standard unit for reporting atmospheric pressure.

The attopascal (symbol: aPa) is an SI-derived unit of pressure equal to one quintillionth (10^-18) of a pascal. It is an extremely small pressure unit used mainly in theoretical physics, nanotechnology, and scientific research involving ultra-low pressure measurements. The attopascal uses the SI prefix atto, representing a factor of 10^-18.

One attopascal is equal to 0.000000000000000001 pascal, 0.001 femtopascal, 0.000000001 nanopascal, 1×10^-23 bar, and 9.86923×10^-24 standard atmosphere. Although rarely used outside research, the attopascal is part of the complete SI pressure scale.