How many bars are in 1 psi?

1 psi equals 0.0689475729 bars, using the exact defined conversion factor rather than an estimate.

How do I convert psi to bar?

Multiply the psi value by 0.06894757293. The converter above does this instantly to whatever precision you set.

How do I convert bar back to psi?

Use the reverse factor: 1 bar equals 14.50377377 psi. You can also use the swap control in the converter above to flip the direction instantly.

Is the psi to bar conversion exact?

Yes. A bar is defined as exactly 100,000 pascals, close to (but distinct from) one standard atmosphere (101,325 Pa). That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.

PSI to Bars Converter

Q: What is a psi?

PSI (psi) measures pressure. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. It is classified as a US/imperial customary unit.

Q: What is a bar?

Bar (bar) measures pressure. A bar is defined as exactly 100,000 pascals, close to (but distinct from) one standard atmosphere (101,325 Pa). It is classified as a Non-SI metric unit accepted for use with SI.

About Converting PSI to Bars

PSI and Bar both show up on pressure gauges — psi is standard on US tire and tool specifications, while bar is the everyday pressure unit across most of the rest of the world. PSI is typically associated with united States (standard pressure unit for tires, tools, and plumbing), while Bar is typically associated with widely used in Europe and most of the world for tire pressure, weather, and industrial pressure.

Formula

bars = psi × 0.0689475729317

This factor comes from each unit's defined relationship to the category's base unit: 1 psi equals 6894.75729317 base units, and 1 bar equals 100000 base units, so dividing one by the other gives the direct psi-to-bar factor of 0.0689475729317.

Simple example

1 psi × 0.06894757293 = 0.0689475729 bar

1 psi = 0.0689475729 bars.

Real-world example

35 psi × 0.06894757293 = 2.413165053 bar

35 psi = 2.413165053 bars. 35 psi converts to about 2.41 bar, a pressure in the typical range for passenger car tires.

Conversion table

PSI (psi)	Bar (bar)
1 psi	0.0689475729 bar
5 psi	0.3447378647 bar
10 psi	0.6894757293 bar
25 psi	1.723689323 bar
50 psi	3.447378647 bar
100 psi	6.894757293 bar

Reverse conversion: Bar to PSI

0.0689475729 bar × 14.50377377 = 0.9999999995 psi

0.0689475729 bars = 0.9999999995 psi.

psi = bars × 14.503773773

For a page dedicated to this direction, see Bar to PSI.

PSI vs. Bar

Aspect	PSI	Bar
Family	US/imperial customary unit	Non-SI metric unit accepted for use with SI
Typical use	Tire pressure specifications in the US	Tire pressure specifications outside the US
Where it's used	United States (standard pressure unit for tires, tools, and plumbing)	Widely used in Europe and most of the world for tire pressure, weather, and industrial pressure

Understanding the PSI

PSI (psi) measures pressure. PSI (pounds-force per square inch) equals exactly 6,894.757293168 pascals. It is classified as a US/imperial customary unit.

Where it's used: United States (standard pressure unit for tires, tools, and plumbing)

Uses of the PSI today

Tire pressure specifications in the US
Hydraulic and pneumatic system ratings
Plumbing, compressed-air tools, and industrial equipment ratings

History of the PSI

PSI is a derived unit from the pound-force and the inch, both themselves standardized through English and later international agreements rather than invented as a pressure unit from scratch.

It became the default pressure unit in US engineering as pound-force and inch-based measurement dominated American industry through the 19th and 20th centuries, and it remains in everyday use for tires and tools even as most other measurements in the US context stay imperial.

Historical origin. PSI was not the invention of a single named person; it developed through the process described above.

Understanding the Bar

Bar (bar) measures pressure. A bar is defined as exactly 100,000 pascals, close to (but distinct from) one standard atmosphere (101,325 Pa). It is classified as a Non-SI metric unit accepted for use with SI.

Where it's used: Widely used in Europe and most of the world for tire pressure, weather, and industrial pressure

Uses of the Bar today

Tire pressure specifications outside the US
Meteorology (weather maps commonly use millibars, hPa)
Industrial and hydraulic pressure ratings in metric-system countries

History of the Bar

The bar was proposed by Norwegian meteorologist Vilhelm Bjerknes around 1906 as a convenient round pressure unit close to atmospheric pressure, derived from the CGS unit system (one bar equals one million dynes per square centimeter).

Though not an SI unit, the bar remains in wide practical use, particularly in meteorology (as the millibar, now more often written as the equivalent hectopascal) and in tire and hydraulic pressure specifications across most of the world.

Historical origin. Bar was not the invention of a single named person; it developed through the process described above.

PSI — sources

NIST Special Publication 811 — Guide for the Use of the International System of Units — Documents conversion factors for psi and other US customary pressure units.

Bar — sources

BIPM SI Brochure — Non-SI units accepted for use with SI — Lists the bar among accepted non-SI pressure units.

PSI to Bars Converter — psi to bar

Pressure Converter