Pounds per Square Inch to Millibars Converter

To convert a measurement in pounds per square inch to millibars, multiply the value by 68.947573. The conversion factor comes from the relationship between both units and the pascal.

For example, to convert 5 psi to millibars: 5 × 68.947573 = 344.737865 mbar.

Pounds per square inch (psi) is an imperial unit of pressure equal to the force of one pound-force applied to an area of one square inch, or about 6,894.76 pascals. Rooted in the imperial system, psi remains the dominant pressure unit in the United States. It appears on tire gauges, air compressors, and hydraulic equipment throughout North America.

Common uses of pounds per square inch include: Tire pressure in the United States; Air compressors and pneumatic tools; Hydraulic system ratings; Plumbing and water pressure specifications.

A millibar equals one thousandth of a bar, or 100 pascals, and is equivalent to the hectopascal used in modern meteorology. The millibar dominated weather reporting for much of the 20th century. It is numerically identical to the hectopascal (hPa) that officially replaced it, so 1013 mbar and 1013 hPa describe the same sea-level pressure.

Common uses of millibars include: Atmospheric pressure in weather forecasts; Barometer and altimeter readings; Aviation weather reporting; Storm and hurricane intensity tracking.

Here are some common values converted:

1 psi = 68.947573 mbar 5 psi = 344.737865 mbar 10 psi = 689.475729 mbar 50 psi = 3,447.3786 mbar 100 psi = 6,894.7573 mbar