Bar to PSI
Convert any value from bar to psi with full precision. Use the converter above for instant results, or read on for the exact formula, worked examples, common uses, and answers to frequently asked questions.
📊 Quick Conversion Table
About the Bar to PSI conversion
Pressure conversions are used in physics, engineering, medicine, meteorology, and many industrial processes. The SI unit is the pascal, but bar, psi (pounds per square inch), atmospheres, torr, and mmHg are common in their respective fields.
This page focuses specifically on converting bar to psi. Use the converter above for instant results, or read on for what each unit is, the exact formula, a worked example, and answers to common questions.
Understanding bar and psi
What is a bar?
The bar equals 100,000 pascals and is very close to average atmospheric pressure at sea level. It is common in weather reporting, scuba diving, and industrial pressure gauges.
What is a psi?
Pounds per square inch, or psi, is one pound-force spread over one square inch, about 6,895 pascals. It is the standard pressure unit in the United States for tires, compressors, and hydraulics.
How a bar compares to a psi
The bar is the larger of the two units: one bar is about 14.50377377 psi. Because the psi is smaller, the same length or quantity works out to a larger number when you measure it with that unit. Knowing which unit is larger is a quick way to sanity-check a conversion: if the numbers move in the wrong direction, the two units have probably been swapped.
Conversion formula
The exact mathematical relationship between bar and psi is:
1 bar = 14.50377377 psi
So to convert a value V from bar to psi, use:
Vpsi = Vbar × 14.50377377
To go in the opposite direction:
Vbar = Vpsi × 0.06894757
These factors come from the international definitions published by NIST, BIPM, and ISO 80000 and are exact within their respective standard systems. The converter applies them with full floating-point precision.
Worked example
Using the formula above, here are some common values converted from Bar to PSI:
| Bar | PSI |
|---|---|
| 1 | 14.503774 |
| 5 | 72.518869 |
| 10 | 145.037738 |
| 25 | 362.594344 |
| 50 | 725.188689 |
| 100 | 1450.377377 |
Sources and accuracy
The pascal equals one newton per square meter (BIPM, NIST). Standard atmospheric pressure equals exactly 101,325 Pa. One bar equals exactly 100,000 Pa. One psi equals exactly 6,894.757293168 Pa. One torr equals exactly 101,325 / 760 Pa.
Conversion factors are cross-checked against the NIST SP 811 guide, the BIPM SI brochure, and ISO 80000, plus published historical references for older unit systems. For mission-critical work such as medical dosing, legal-for-trade measurement, aerospace, or large-scale engineering, always verify independently with the original source.
Practical tips
When reading weather reports, "millibars" and "hectopascals" are the same unit (1 mbar = 1 hPa = 100 Pa). Standard sea-level pressure is 1013.25 mbar or hPa.
Frequently asked questions
How many psi are in one bar?
One bar equals 14.50377377 psi. To convert, multiply your bar value by 14.50377377.
Which is bigger, a bar or a psi?
The bar is bigger. One bar equals about 14.50377377 psi.
How accurate is this bar to psi converter?
It uses the official international conversion factors from NIST and BIPM with full double-precision floating-point accuracy. For everyday use the result is precise to many more decimal places than any practical measurement requires.
Can I convert psi back to bar as well?
Yes. Use the swap button above to reverse the From and To fields, or change either dropdown to any unit in the pressure category. The calculation runs entirely in your browser, so it also works offline once the page has loaded.