What is a pressure converter?
Convert pressure among pascals, kilopascals, megapascals, bars, atmospheres, psi, torr, millibars, and conventional mmHg. It is designed for quick everyday and technical unit comparisons without requiring sign-up or server-side calculation.
How does this converter work?
The calculator converts the entered value through a common reference unit or an exact scale relationship, then converts that reference value to the selected target unit. Intermediate values are not rounded. This follows the general NIST approach of choosing an appropriate conversion factor, canceling units and rounding the final quantity rather than intermediate steps.
Which units are supported?
Pascal, kilopascal, megapascal, bar, millibar, standard atmosphere, psi, torr and conventional mmHg.
Use the unit labels carefully when similar names can represent different systems. The selected units are always shown again in the result panel.
How do you use this pressure converter?
- Enter the numerical value you want to convert.
- Select the starting unit.
- Select the target unit, or use Swap Units to reverse them.
- Keep precision on Automatic or choose a significant-digit setting.
- Select Convert, then review the conversion relationship and result details.
Conversion example
1 standard atmosphere equals exactly 101,325 pascals and 760 torr.
Accuracy, definitions and rounding
A numerical pressure conversion does not tell you whether a value is gauge pressure or absolute pressure. Keep the same pressure reference when comparing results.
For important engineering, scientific, commercial or regulatory work, confirm that the unit definition, measurement uncertainty and required significant digits match the standards used in your application.
Pressure conversion in equipment and weather work
Pressure values appear in several different settings, and the surrounding label matters as much as the number. Tire and compressor gauges commonly show pressure relative to the surrounding atmosphere, while some engineering specifications use absolute pressure. Weather reports use atmospheric pressure, often in hectopascals or millibars, and equipment sheets may use pascals, kilopascals, bars or pounds per square inch. Convert only values that describe the same pressure reference.
For maintenance work, copy the unit printed beside the original reading and compare the result with the unit required by the manual. Do not use a converted value to override a manufacturer limit, calibrated gauge or safety procedure. Rounding can also matter near a minimum or maximum specification, so keep additional digits during the calculation and round only the final value to the precision the task requires.
Frequently asked questions
Sources and methodology
The calculation relationships and explanatory notes are based on authoritative measurement references. Links open the original source so you can verify the unit definitions and conversion guidance.