Bar to pounds per square inch
Multiply bar by 14.5038 to get pounds per square inch.
2.5 bar = 36.2594 psi
How to convert bar to pounds per square inch
The pound per square inch is pounds-force per square inch, exactly 6894.757293168 pascals. The bar is exactly 100 000 pascals (100 kPa), close to one atmosphere.
Worked example — 2.5 bar: 2.5 × 14.5038 = 36.2594 psi.
Bar to pounds per square inch table
| Bar | Pounds per square inch |
|---|---|
| 1 bar | 14.5038 psi |
| 1.5 bar | 21.7557 psi |
| 2 bar | 29.0075 psi |
| 2.2 bar | 31.9083 psi |
| 2.5 bar | 36.2594 psi |
| 3 bar | 43.5113 psi |
| 4 bar | 58.0151 psi |
| 5 bar | 72.5189 psi |
| 10 bar | 145.0377 psi |
Reverse and related
About bar and pounds per square inch
Bar (bar)
1 bar = 14.5038 psiDefinition. Exactly 100 000 pascals (100 kPa), close to one atmosphere
History and origin
The bar was introduced in the early twentieth century by the meteorologist Vilhelm Bjerknes, defined as exactly 100 000 pascals, close to average sea-level air pressure. Its name comes from the Greek for weight.
Current use
The bar is common outside the United States for tyre pressure, diving and weather, where the closely related millibar is also used.
Source: NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi)
Pound per square inch (psi)
1 psi = 0.0689476 barDefinition. Pounds-force per square inch, exactly 6894.757293168 pascals
History and origin
The pound per square inch comes from the imperial system, expressing pressure as pounds-force spread over a square inch. It equals about 6895 pascals.
Current use
Psi is the everyday pressure unit in the United States for tyre pressure, plumbing and compressed air.
Source: NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi)
Where people use this
Bar: tyre pressure outside the US, diving, weather. Pounds per square inch: tyre pressure in the US, plumbing, compressed air. A 2 bar tyre is about 29 psi.
Every value is carried to full double precision; the display is rounded.
Both units are defined in NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi).
Questions people ask
How many psi is 2 bar?
A 2 bar tyre is about 29 psi, and 2.5 bar is about 36.3 psi.
How many psi in a bar?
One bar is about 14.5 psi. To convert bar to psi, multiply by 14.5.
How do you convert bar to psi?
Multiply the bar by 14.5, so 3 bar is about 43.5 psi.
How many psi is 1.5 bar?
1.5 bar is about 21.8 psi.