Bar to Psi

Welcome to bar to psi, our website dedicated to the pressure conversion from the unit bar to the unit pound per square inch also known as pound-force per square inch. Here you can find everything about the bar to pounds per square inch conversion, including the formula and a converter. If you have been looking for how many psi in a bar, or bars to psi, then you have come to the right site, too. Keep reading to learn all about the pressure conversion.

Although the bar is a metric unit, it does not belong to the International System of Units (SI). One bar is defined as 100000 Pascal (Pa), a SI derived unit. As 1 Pa is equal to 0.0001450377 psi, one bar is exactly 14.50377 psi. One Pa is the pressure resulting from a force of one newton per square meter, whereas one pound per square inch (psi) is the pressure when one pound-force applied to the area of one square inch.

Besides the usual abbreviation psi for the avoirdupois unit pound-force per square inch, you may also come across the short forms lbf/sq in, lbf/in2, lbf/in2 and lbf/sq in. The terms bar to lbf/sq in, bar to lbf/in2, bar to lbf/in2 and bar to lbf/sq in thus all mean bar into psi.

In the next section we show you how to convert bars to psi. We recommend you also check out what bar to pounds per square inch gauge stands for. You can find it a little bit further down on this page.

Convert Bar to Psi

As follows from the explanations above, the bar to psi formula is: [psi] = [bar] x 14.50377.

So, to convert the pressure multiply bar by 14.50377. For example, to change 1.5 bar multiply 1.5 by 14.50377 to obtain ~ 21.76 psi, the pound force per square inch.

The pressure unit bar was invented by William Napier Shaw, a British meteorologist. At the time he invented the bar (1909), he was the director of the institution today known as the United Kingdom’s national weather service.

Our frequent conversions include, for example:

In terms of math, the conversion bar psi is a simple multiplication. However, using a calculator like the one below is way easier to convert the pressure to psi than applying the conversion formula manually.


Our bar to psi converter changes the pressure as you enter the numbers. Use a decimal point for fractions, and note that you can toggle between bar and mbar if you like.

Change Bar to Psi


If this calculator has been useful to you, then bookmark us now as bar psi.

Here you can learn all about converting psi to bar. Note that you also find frequent pressure conversions using our search form in the side bar. Enter, for instance, x bar in psi.

Read on to find out what bar(a) and bar(g) means. This can really be quite important!

Additional Information

You already know most about the bar to pound-force per square inch conversion, but we haven’t yet explained the difference between bar absolute (bara), also known as bar(a), and bar gauge (barg), aka bar gage, sometimes denoted bar(g).

Bara refers to vacuum pressure conditions. To obtain the bara value one has to add the local pressure to any pressure gauge reading in bar: bara = barg + local pressure.

Barg, in turn, refers to atmospheric pressure conditions: barg = bara – local pressure.

At sea level, the standard local pressure is defined as 1.01325 bar. Throughout this website we use 1013 mbar or 14.7 psi for absolute pressure approximations.

For example, 0 meter above sea level, an inflated, cold, care tire gauged 2.13737 bar has an absolute pressure of approximately 2.13737 + 1.01325 = 3.15062 bar.

  • If you want to convert barg to psig you can forget about the extra 1.01325 bar when reading the pressure gauge in bar, also known as barg or bar(g).
  • If you want to convert bara to psia you can forget about the extra 1.01325 bar if you have a value in in bar absolute, also known as bara or bar(a).
  • If you calculate the difference between pressures in either barg or bara, don’t take local pressure into account as long as you don’t mix absolute and relative units.
  • If you convert a pressure from bar to pounds per square inch, you don’t have to think about local pressure as long if you don’t mix relative and absolute units.

In case a gauge pressure was relative to something different than to ambient atmospheric pressure, then the unit would be called bard, for bar differential, or bar(d).

Below you can find the bar psi pressure conversions which are frequently sought. To prevent ambiguity, bar means bar absolute, abbreviate as bara or bar(a), and psi stands for psi absolute, unless otherwise stated:

Bar to Psia

The bar to psia conversion is as follows: bar to psia = bar x 14.50377. That is, to convert bar to psia you have to multiply the bar value by 14.50377.

To convert bar to psia you can use our calculator.

Bar to Psig

The bar to psig conversion can be made with this equation: bar to psig = (bar x 14.50377) – 14.7. The term psig is used to differentiate psi from psia.

To convert bar to psig use the formula given in this section.

Barg to Psig

As bar(g) or barg stands for gauge pressure, and psig also denotes a gauge pressure, the formula is barg to psig = bar x 14.50377.

You can make use of our calculator to convert barg to psig.

Barg to Psia

As bar(g) or barg stands for gauge pressure, but psia denotes a vacuum pressure, the formula is barg to psia = (bar x 14.50377) + 14.7 psi at sea level.

Use the formula in this section to change barg to psia.

Barg to Psi

When talking about barg to psi it either means barg to psig or barg to psia, probably the former. To convert barg to psi find out whether psig or psia are meant.

Using the search function in the sidebar, you can also look conversions like bar to psia up. Give it a try now, yet make sure to also check out mbar to psi further down this page.

Barg to Bara

The barg to bara conversion is as follows: barg to bara = barg + local atmospheric pressure. That is, at sea level, to convert barg to bara you have to add ~ 1.01325 bar to the barg value.

Barg to Bar

For the conversion barg to bar we assume that bar stands for bar absolute, so we have the barg to bara case just discussed above.

Bara to Barg

The bara to barg conversion is as follows: bara to barg = bara – local atmospheric pressure. Therefore, to convert bara to barg you have to subtract ~ 1.01325 bar from the bara value.

Bar to Barg

For the conversion bar to barg we assume that bar stands for bar absolute, so we have bara to barg case, which you can find just above.

Next, we will have a look at the multiples and submultiples of bar.

Mbar to Psi

Not only in meteorology it is common to come across derived units such as the millibar, a thousandth of bar. These metric prefixed units of pressure include:

megabar (Mbar) = 106 (1000000) bar
kilobar (kbar) = 103 (1000) bar
hectobar (hbar) = 102 (100) bar
decabar (dabar) = 101 (10) bar
decibar (dbar) = 10-1 (0.1) bar
centibar (cbar) = 10-2 (0.01) bar
millibar (mbar) = 10-3 (0.001) bar
microbar (μbar) = 10-6 (0.000001 bar

To convert bar to pound-force per square inch using these derived units divide 14.50377 by the value of the metric prefix. The most important submultiple of the unit bar is the millibar (mbar).

To convert mbar to psi use the formula [psi] = [mbar] x 0.01450377.

Just make sure that you understand the difference between Mbar (megabar), with a capital letter M, and mbar (millibar), with a small letter m.

When converting mbar to psi the factor between and m and M is 1000000000!


We are coming to the end of our article.

The following image sums the conversion up:

Bar to Psi

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