Convert Millimeter of Water to Petapascal (mmH2O to Petapascal)

Millimeter of Water (mmH2O) and Petapascal (Petapascal) are both units of pressure. With the conversion form below, you can effortlessly and accurately convert millimeter of water to petapascal. This free online calculator tool makes it simple and easy to perform the conversion from mmH2O unit to the Petapascal 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 millimeter of water (symbol: mmH₂O or mmH2O) is a non-SI unit of pressure defined as the pressure exerted by a one-millimeter column of water under standard gravity. It is commonly used in ventilation systems, clean rooms, HVAC engineering, and laboratory instruments to measure small pressure differences. Although the pascal is the SI unit of pressure, the millimeter of water remains a practical unit for low-pressure applications. It is based on the concept of a water column.

One millimeter of water is equal to 9.80665 pascals, 0.1 centimeter of water, 0.0000980665 bar, 0.00142233 pounds per square inch, and 0.00980665 kilopascal. The millimeter of water is widely used for measuring very low gas and liquid pressures.

The petapascal (symbol: PPa) is an SI-derived unit of pressure equal to one quadrillion (10¹⁵) pascals. It is an extremely large pressure unit used primarily in astrophysics, geophysics, high-energy physics, and theoretical research involving exceptionally high pressures. The petapascal uses the SI prefix peta, representing a factor of 10¹⁵.

One petapascal is equal to 1,000 terapascals, 1,000,000 gigapascals, 1,000,000,000 megapascals, 10,000,000,000 bars, and 1×10¹⁵ pascals. Although rarely encountered outside advanced scientific research, the petapascal is part of the complete SI pressure scale.