The calculator converts each value to pascals first, then divides by the target unit factor. It accepts positive and negative numbers because gauge pressure can fall below ambient pressure. It does not add or subtract atmospheric pressure, so you should keep gauge readings with gauge readings and absolute readings with absolute readings.
Private browser utility / Converters
Free Pressure Converter
Runs entirely in your browser - no upload, no sign-up.
Unit conversion only. Gauge and absolute pressure use different zero points, so psig and psia are not adjusted automatically.
Converted pressureEnter a pressure value to see every unit
How do you convert pressure units?
Choose the pressure unit you have, enter a value, and select the unit you need. This pressure converter updates instantly between PSI, bar, pascals, atmospheres, Torr and mercury-column units. It also shows the same pressure across every supported unit, so you can compare engineering, weather, lab and tire-pressure readings at once.
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How to use
- 01Enter the pressure
Type a value in the From field. Decimal commas, decimal points, scientific notation and negative gauge values are supported.
- 02Choose the source unit
Select the unit printed on your gauge, specification, forecast or lab instrument.
- 03Choose the target unit
Pick the pressure unit you need. The main result and the all-units grid update immediately.
- 04Copy or reverse it
Copy the complete conversion, or swap the units to reverse the direction without retyping the value.
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Who it's for
- Drivers and cyclists comparing tire recommendations in PSI, bar and kPa when a pump or manual uses a different unit.
- Engineers and technicians checking specifications written in MPa, bar, PSI, ksi or kilogram-force per square centimeter.
- Weather watchers converting station pressure between hPa, mbar, inHg and standard atmospheres.
- Lab and vacuum teams comparing pascals, Torr and conventional mmHg without treating every mercury unit as identical.
- HVAC and plumbing teams translating gauge readings while keeping the original gauge or absolute reference clear.
FAQ
Is this pressure converter free?
Yes. The pressure converter is free with no sign-up, download or usage cap for normal browser use. It performs each calculation locally, and the value you enter is not uploaded to a server.
Which pressure units can I convert?
You can convert Pa, kPa, MPa, hPa, bar, mbar, PSI, ksi, standard atmospheres, Torr, conventional mmHg, inHg and kgf/cm^2. The main result targets your chosen unit, while the reference grid shows every supported unit at once.
How many PSI are in one bar?
One bar is approximately 14.5037738 PSI. Bar is defined as exactly 100,000 Pa, while one PSI is about 6,894.757293 Pa. Enter a bar value and select PSI for a result calculated from those base factors.
How many kPa are in one PSI?
One PSI is approximately 6.894757293 kPa. For a common tire reading, 35 PSI is about 241.3165 kPa or 2.4132 bar. The tool keeps more precision internally than it displays, which helps reverse conversions remain stable.
Are hPa and mbar the same?
Yes. One hectopascal and one millibar both equal exactly 100 pascals, so their numerical values match. Weather services may use either label for atmospheric pressure, such as 1013.25 hPa or 1013.25 mbar.
Are Torr and mmHg the same?
They are nearly equal but have slightly different conventional definitions. One Torr is exactly one 760th of a standard atmosphere, while conventional mmHg uses a mercury-column factor. Most everyday readings look identical, but precision work should preserve the unit name.
Can I convert negative pressure values?
Yes. Negative values are useful for gauge pressure below ambient, such as a partial vacuum. The converter changes units only. It does not turn gauge pressure into absolute pressure, because that requires the local atmospheric reference.
Does the converter distinguish psig from psia?
It converts the PSI magnitude but does not change the reference zero. PSIG is relative to ambient pressure, while PSIA is relative to a perfect vacuum. To change between them, add or subtract the applicable atmospheric pressure before converting units.