Bar to PSI Converter

Instantly convert bar to PSI (Pounds per Square Inch) and see equivalent values for kPa and atm. Perfect for tire pressure and engineering needs.

Pressure Units

Enter a value in one field and let the converter fill each of the other units.

How to Use This Converter

Choose the pressure unit you want to convert from, enter the numeric value, and click Calculate (or wait for the inputs to update automatically after typing). The other fields show the equivalent values instantly.

Methodology

Every value is converted through Pascals (Pa), the SI base unit for pressure. The calculator multiplies the source value by the Pascal factor for that unit before converting to the remaining units. This keeps the results consistent across units and decimal precision.

Full original guide (expanded)

Bar to PSI Converter

A complete pressure unit conversion tool for tire pressure and engineering. Enter a value in any field to instantly convert between Bar, PSI, Kilopascals (kPa), and Atmospheres (atm).

How to Convert Bar to PSI

Converting from bar to Pounds per Square Inch (PSI) is the most common pressure conversion for drivers, as European and US tire pressure gauges use different units. The conversion is straightforward.

The Conversion Formula

The relationship between bar and PSI is based on their definitions in Pascals:

1 bar = 100,000 Pascals (Pa)
1 PSI = 6,894.757 Pascals (Pa)

From this, we get the direct conversion factor:

  • Bar to PSI: PSI = bar × 14.50377
  • PSI to Bar: bar = PSI / 14.50377 (or PSI × 0.0689476)

For a quick mental estimate, you can just remember 1 bar ≈ 14.5 psi.

Bar vs. atm: What's the Difference?

A common point of confusion is the difference between bar and atm (standard atmosphere). They are very close but not the same.

  • 1 bar is defined as exactly 100,000 Pascals (Pa).
  • 1 atm is defined as exactly 101,325 Pascals (Pa).

Therefore, 1 atmosphere is slightly larger than 1 bar (1 atm = 1.01325 bar). The converter keeps both units in sync for scientific accuracy.

Common Tire Pressure Conversion Chart

A quick reference chart for common car tire pressures.

Bar PSI (approx.) kPa (approx.)
2.0 bar29.0 psi200 kPa
2.1 bar30.5 psi210 kPa
2.2 bar31.9 psi220 kPa
2.3 bar33.4 psi230 kPa
2.4 bar34.8 psi240 kPa
2.5 bar36.3 psi250 kPa

Frequently Asked Questions (FAQ)

What is the formula for bar to PSI?

The formula is: PSI = bar × 14.50377.

How many PSI are in 1 bar?

There are 14.50377 PSI in 1 bar. For quick mental math, you can approximate 1 bar ≈ 14.5 PSI.

How many PSI in 2.2 bar?

To convert 2.2 bar to PSI (a common tire pressure), you multiply 2.2 by 14.50377, which equals 31.908 PSI (often rounded to 32 PSI).

Formulas

Bar to Pascal: 1 bar = 100,000 Pascals

PSI to Pascal: 1 PSI = 6,894.757 Pascals

Conversion path: bar → Pascal → target unit ensures consistent rounding.

Citations

NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures

NIST — SI units — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/owm/metric-si/si-units

Changelog

Version: 0.1.0-draft · Last code update: 2026-01-19

  • Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido Last Updated: 2026-01-19 Version 0.1.0-draft
Audit: Complete
Version 1.5.0