Pressure Converter
Convert between any two pascal units in your browser — instant, accurate, and private.
Example
1 Pa = 0.001 kPa. Switch the unit menus to convert between any pair.
How it works
Every value is converted through a single pascal base unit using internationally defined conversion factors, so any from/to pair stays consistent.
Good to know
Pressure conversion sits behind everyday tasks that rarely advertise it: checking a tire against a manufacturer's spec, sizing a pump or air compressor, reading a weather barometer, calibrating a vacuum chamber, or interpreting a blood-pressure or HVAC gauge. The trouble is that pressure gets reported in a different unit depending on who built the device — a German tire chart in bar, an American one in PSI, a lab manometer in torr, and an aviation altimeter in inches of mercury — so moving between fields almost always means moving between units.
These nine units come from three different worlds. The pascal (and its kilo- and mega- multiples) is the pure SI unit, defined as one newton spread over one square metre. The bar and atmosphere are metric-era "convenience" units sized to roughly match air pressure at sea level. PSI is the imperial/US-customary survivor, pounds-force per square inch. And millimetre of mercury, torr, and inch of mercury are the old fluid-column units, born from literally measuring how high a pillar of mercury a pressure could hold up.
A few rules of thumb make the relationships memorable: 1 bar is almost exactly 1 atmosphere (1.01325 bar) and equals 100 kPa, while standard atmosphere is about 14.7 PSI, 760 mmHg, and 29.92 inHg. For quick mental math, bar to PSI is "times 14.5", and the torr is defined to be identical to the millimetre of mercury, so those two numbers are interchangeable to the precision most people need.
The most common mistake is mixing up gauge and absolute pressure: a tire reading "32 PSI" is gauge (above the surrounding air), whereas a converter works in raw unit ratios and won't add or subtract the ~14.7 PSI of atmosphere for you. Also watch the small definitional gaps — mmHg and torr differ from each other by under two parts per million, and inHg depends on a reference temperature for mercury's density, so a result that looks "off" in the last digit is usually rounding, not error.
Frequently asked questions
What does the pressure converter do?
It converts between common pascal units instantly. Pick a unit to convert from and a unit to convert to, type a value, and the result updates live.
Which units does this converter support?
It includes 9 units: Pascal, Kilopascal, Megapascal, Bar, Atmosphere, Pound/inch², Millimeter of mercury, Torr, Inch of mercury.
Is this converter free and private?
Yes. It runs entirely in your browser, so your inputs never leave your device, there is no sign-up, and it works offline once loaded.
Are the conversions exact?
Conversions use internationally defined factors and are exact where the definitions are exact (for example, 1 inch = 2.54 cm). Displayed results are rounded for readability.
People also ask
How many PSI are in 1 bar?
1 bar equals about 14.5038 PSI. So a 2-bar reading is roughly 29 PSI, and a quick estimate is to multiply bar by 14.5.
What is 1 atmosphere in kPa and PSI?
One standard atmosphere is 101.325 kPa, which is about 14.696 PSI. It also equals 1.01325 bar, 760 mmHg, and 29.92 inHg.
Is mmHg the same as torr?
Effectively yes. The torr is defined as 1/760 of a standard atmosphere, and 1 mmHg is essentially identical, differing by less than 0.000015 percent, so the two are interchangeable for almost all practical use.
How do I convert kPa to bar?
Divide kilopascals by 100. For example, 250 kPa is 2.5 bar, since 1 bar equals exactly 100 kPa.
What does 760 mmHg mean?
760 mmHg is standard sea-level atmospheric pressure, equal to 1 atmosphere. It is the height of a mercury column the surrounding air can support, and it also equals 760 torr and about 101.325 kPa.
How many pascals are in a bar?
1 bar equals 100,000 pascals (100 kPa or 0.1 MPa). The pascal is a small unit, which is why bar and kPa are more convenient for tires, weather, and industrial pressures.
What is the difference between MPa and bar?
1 megapascal equals 10 bar. MPa is common in engineering and material-strength specs, while bar is more typical for fluids and pneumatics, but they convert with a simple factor of 10.
Why does my converted pressure look slightly off from a printed chart?
Most charts round their values, and units like inHg depend on a reference temperature for mercury density. A difference in the final digit is normally rounding rather than a real error. Also check whether the chart uses gauge versus absolute pressure.
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