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Pressure Converter

Convert psi, bar, pascal, kPa, atmospheres, mmHg and torr.

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Check this before you rely on it. This converter is provided free and without warranty, and its results are not professional advice.

Popular pressure conversions

psi to barbar to psikPa to psi

Pressure unit reference chart

What one of each unit is worth in pascals, the base unit used for every conversion in this category.

Pressure units expressed in pascals
UnitSymbol1 unit in Pa
pounds per square inchpsi6,894.757293 Pa
barbar100,000 Pa
pascalsPa1 Pa
kilopascalskPa1,000 Pa
standard atmospheresatm101,325 Pa
millimeters of mercurymmHg133.3223874 Pa
torrTorr133.3223684 Pa
millibarsmbar100 Pa
inches of mercuryinHg3,386.38864 Pa
megapascalsMPa1,000,000 Pa
kilogram-force per square centimeterkgf/cm²98,066.5 Pa

Pressure units explained

Pounds per square inch (psi)

One psi is one pound-force per square inch, about 6,894.76 pascals. It is the standard pressure unit for tyres and hydraulics in the US.

Bar (bar)

One bar is exactly 100,000 pascals, very close to average atmospheric pressure at sea level.

Pascals (Pa)

The pascal is the SI unit of pressure: one newton per square meter.

Kilopascals (kPa)

A kilopascal is 1,000 pascals. It is the metric unit on tyre placards and in engineering specifications; standard atmospheric pressure is 101.325 kPa.

Standard atmospheres (atm)

The standard atmosphere is defined as exactly 101,325 pascals — the reference sea-level pressure.

Millimeters of mercury (mmHg)

A millimeter of mercury is about 133.32 pascals. It is the unit used for blood pressure readings.

Torr (Torr)

One torr is exactly 1/760 of a standard atmosphere, which makes it almost — but not quite — identical to a millimeter of mercury. It is the working unit of vacuum systems.

Millibars (mbar)

A millibar is 100 pascals, identical to a hectopascal. It is the standard unit in weather reports.

Inches of mercury (inHg)

An inch of mercury is about 3,386.39 pascals. Aircraft altimeters and US weather reports use it; the standard sea-level setting is 29.92 inHg.

Frequently asked questions

What is the base unit of pressure?

This converter routes every pressure conversion through the pascal. Converting from one unit to another means converting to pascals first and then out again, which keeps every pair consistent with every other pair.

How accurate are these pressure conversions?

Results are shown to 10 significant digits using exact defined factors wherever a unit has one. No rounding is applied beyond that final display step.

All pressure conversions

Every pressure conversion page on this site, 88 in total.