1 pound per square inch [psi] = 68.947573 millibar [mbar]
Example: 1 pound per square inch [psi] equals 68.947573 millibar [mbar].
Examples
1 pound per square inch [psi] = 68.947573 millibar [mbar]
2 pound per square inch [psi] = 137.895146 millibar [mbar]
5 pound per square inch [psi] = 344.737865 millibar [mbar]
10 pound per square inch [psi] = 689.475729 millibar [mbar]
20 pound per square inch [psi] = 1378.951459 millibar [mbar]
25 pound per square inch [psi] = 1723.689323 millibar [mbar]
Practical Uses for psi to millibar
tire inflationcompressors and pumpsHVAC and plumbingengineering specifications
Sources and Accuracy
Pressure conversions use pascal as the reference unit and include common engineering, weather, tire, and laboratory pressure units.
Displayed results are rounded for readability. The calculator keeps enough precision for everyday use and switches to scientific notation for very large or very small values. Last reviewed: 2026-08-14.
About These Units
pound per square inch [psi]
Definition
Pound per square inch is a pressure unit showing pounds-force applied over one square inch.
History
PSI comes from imperial force and area units and remains common in mechanical and pressure-gauge contexts.
Current use
PSI is used for tire pressure, compressors, plumbing, hydraulics, gas cylinders, and equipment ratings.
millibar [mbar]
Definition
The millibar (mbar) is a pressure unit used to express measurements in this converter.
History
This unit is included because it appears in practical measurement systems, technical references, product specifications, or everyday conversion needs.
Current use
Use millibar when comparing pressure values, checking specifications, converting between systems, or preparing quick estimates.
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How to Convert
Enter the value in the “From value” field.
Confirm the source unit is pound per square inch [psi].
Confirm the target unit is millibar [mbar].
Read the instant result and formula.
Where This Conversion Is Used
tire inflationcompressors and pumpsHVAC and plumbingengineering specifications