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Pressure Converter

Convert any pressure unit to another with this free pressure converter. It supports 7 units including pascals, kilopascals, bars, pounds per square inch, atmospheres, torr, and more. Pick a conversion below for a dedicated calculator, formula, and reference table. For example, 1 Pa = 0.001 kPa.

All pressure conversions

Pascal → KilopascalPascal → BarPascal → Pound per Square InchPascal → AtmospherePascal → TorrPascal → MillibarKilopascal → PascalKilopascal → BarKilopascal → Pound per Square InchKilopascal → AtmosphereKilopascal → TorrKilopascal → MillibarBar → PascalBar → KilopascalBar → Pound per Square InchBar → AtmosphereBar → TorrBar → MillibarPound per Square Inch → PascalPound per Square Inch → KilopascalPound per Square Inch → BarPound per Square Inch → AtmospherePound per Square Inch → TorrPound per Square Inch → MillibarAtmosphere → PascalAtmosphere → KilopascalAtmosphere → BarAtmosphere → Pound per Square InchAtmosphere → TorrAtmosphere → MillibarTorr → PascalTorr → KilopascalTorr → BarTorr → Pound per Square InchTorr → AtmosphereTorr → MillibarMillibar → PascalMillibar → KilopascalMillibar → BarMillibar → Pound per Square InchMillibar → AtmosphereMillibar → Torr

About these units

Pascal (Pa)

Definition
The pascal (Pa) is the SI unit of pressure, equal to one newton of force per square meter.
History
Named after Blaise Pascal, it was adopted as the SI pressure unit in 1971.
Current use
Pascals and kilopascals are used in science, engineering, and weather reporting.

Kilopascal (kPa)

Definition
A kilopascal (kPa) is 1,000 pascals, a convenient size for everyday pressures.
History
It is a metric multiple of the pascal.
Current use
Kilopascals express tyre pressure and atmospheric pressure in many countries.

Bar (bar)

Definition
A bar is a metric pressure unit equal to 100,000 pascals, close to average sea-level atmospheric pressure.
History
It was introduced by meteorologist Vilhelm Bjerknes in the early 20th century.
Current use
Bars are used in meteorology, diving, and industry to express pressure.

Pound per Square Inch (psi)

Definition
Pounds per square inch (psi) is an imperial pressure unit, the force of one pound over one square inch.
History
It developed with the imperial system and steam-engine engineering.
Current use
Psi is the common pressure unit for tyres and compressed gas in the United States.

Atmosphere (atm)

Definition
A standard atmosphere (atm) is defined as exactly 101,325 pascals, roughly average sea-level pressure.
History
It was standardised as a reference pressure for scientific work.
Current use
Atmospheres are used in chemistry, physics, and diving as a reference pressure.

Torr (Torr)

Definition
A torr is a pressure unit equal to 1/760 of a standard atmosphere, about 133.3 pascals.
History
Named after Evangelista Torricelli, inventor of the barometer, it equals roughly one millimeter of mercury.
Current use
Torr is used in vacuum technology and laboratory science.

Millibar (mbar)

Definition
A millibar (mbar) is one thousandth of a bar, equal to 100 pascals (one hectopascal).
History
It became the traditional unit of meteorological pressure in the 20th century.
Current use
Millibars (or equivalent hectopascals) report atmospheric pressure on weather charts.

Frequently asked questions

What pressure units can I convert?

This pressure converter supports 7 units: pascals, kilopascals, bars, pounds per square inch, atmospheres, torr, millibars. Select any pair below to open a dedicated converter with a formula and conversion table.

How accurate is the pressure converter?

Conversions use exact definitional factors, so results are accurate to the precision you need for science, engineering, and everyday use. Values are rounded only for display.

Is the pressure converter free?

Yes. Every pressure conversion is completely free, needs no sign-up, and runs entirely in your browser — your inputs never leave your device.

Free, private, and instant — every conversion runs in your browser.

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