Bar to psi converter

Convert bar to psi (bar to psi) with the exact factor, a conversion chart and worked steps.

Drafted with AI writing toolsUpdated Checked examples: 3

bar
Try
Psi
psi
Psi: 31.9083023006 psi
Significant figures: 12; Nearest, ties away from zero
Conversion
2.2 bar = 31.9083023006 psi
1 psi in bar
0.06894757293bar

2.2 bar is about 31.9083023006 psi. In the other direction, 1 psi ≈ 0.06894757 bar.

Bar to psi

01,0002,00050100150200barpsi2.2 → 31.9083
Bar to psi chart Rows: 10
BarPsi
0.57.2519
114.5038
1.521.7557
229.0075
2.231.9083
2.536.2594
343.5113
572.5189
10145.0377
2002,900.7548
How it's calculated S
  1. Conversion factor

    1 bar=14.503773773 psi1\ \text{bar} = 14.503773773\ \text{psi}

    Rounded here for display; the calculation uses 50 significant digits.

  2. Multiply

    2.2×14.503773773=31.9083023006 psi2.2 \times 14.503773773 = 31.9083023006\ \text{psi}

About the bar to psi converter

To convert bar to psi, multiply by 14.503773773; to convert back, multiply by 0.0689475729. For example, 2.2 bar is about 31.908302 psi. Displayed factors and results may be rounded.

Bar is used on pumps and pressure equipment. A decimal bar reading can be converted for a gauge with another scale, but the equipment's specified reference and permissible range still apply. Do not confuse a pressure setting with a recommended operating value.

bar: 1 bar = 100,000 Pa = 100 kPa. These values are exact.

Both units are defined exactly. Calculations use 50 significant digits and round only for display.

How to convert bar to psi

Multiply bar by 14.5038: psi = bar × 14.5038. So 2.2 bar = 31.91 psi and 2.5 bar = 36.26 psi. It applies to tire placards, pumps and espresso machines rated in bar, and gauge stays gauge: 2.2 bar on a tire gauge is 31.91 psi on a psi gauge.

Multiply by 14.5 for a quick answer

Multiplying by 14.5 is within 0.03%: 2.2 bar × 14.5 = 31.9 psi, against 31.908 with the full factor. Rounding up to 15 is 3.4% high and would put a 2.2 bar tire at 33 psi, more than a full psi over.

Where 14.5038 comes from

A bar is exactly 100,000 Pa. A psi is one pound-force (4.4482216152605 N) per square inch (0.0254² m²), or 6,894.757 Pa. So 1 bar = 100,000 ÷ 6,894.757 = 14.5037738 psi (NIST SP 811, Appendix B8).

Bar to psi chart

Barpsi, rounded
0.57.251887
114.503774
1.521.755661
229.007548
2.231.908302
343.511321

Higher ratings: 9 bar, the pressure usually quoted for espresso, is 130.53 psi. A dive cylinder filled to 200 bar holds 2,900.75 psi, and one at 232 bar holds 3,364.88 psi.

barg, bara and atmospheric pressure

Specs often add a g or an a: barg is gauge pressure, measured above the surrounding air, and bara is absolute pressure, measured from a vacuum. The conversion keeps the suffix: 2.2 barg is 31.91 psig, and 2.2 bara is 31.91 psia.

To switch reference, add or subtract atmospheric pressure in one unit. The standard atmosphere is 1.01325 bar, or 14.696 psi, so at that pressure a tire at 2.2 barg holds 3.21325 bara, which is 46.60 psia.

Below atmospheric, gauge readings are negative: a partial vacuum of −0.5 barg is −7.25 psig.

Common mistakes

  • Dividing by 14.5. That is the psi-to-bar direction and turns 2.2 bar into 0.15 psi. A psi is the smaller unit, so the psi number is always the larger one.
  • Taking 1 bar as atmospheric pressure. One bar is 14.504 psi, 1.3% short of a standard atmosphere, which puts an absolute figure 0.19 psi low.
  • Confusing bar with kPa or MPa. 2.2 bar is 220 kPa or 0.22 MPa, and kPa to psi gives the same 31.91 psi from 220 kPa.

For the reverse, use psi to bar. The pressure converter covers atm, kgf/cm², mmHg and inHg.

Worked examples

2.2 bar to psi

Bar (bar)
2.2 bar
Psi
31.9083023006 psi

Checked against: Exact-fraction computation from the legal unit definitions

2 bar to psi

Bar (bar)
2 bar
Psi
29.007547546 psi

Checked against: Exact-fraction computation from the legal unit definitions

10 bar to psi

Bar (bar)
10 bar
Psi
145.03773773 psi

Checked against: Exact-fraction computation from the legal unit definitions

Questions

How many psi is one bar?

1 bar is about 14.503773773 psi. bar: 1 bar = 100,000 Pa = 100 kPa. These values are exact.

How do I convert bar to psi?

Multiply by 14.503773773: 2.2 bar × 14.503773773 ≈ 31.908302 psi. To convert back, divide by the same factor. The factor shown may be rounded.

How can I estimate bar in psi without a calculator?

Multiply by 14.5. This is 0.02602% below the exact factor (about 14.503773773), so 2.2 bar comes out as 31.9 psi instead of 31.9083 psi.

About this calculator

psi=bar×14.503773773\text{psi} = \text{bar} \times 14.503773773

Sources

  1. NIST SP 811 (2008), Guide for the Use of the International System of Units, Appendix B
  2. NIST Handbook 44, Appendix C: General tables of units of measurement
  3. BIPM, The International System of Units (SI Brochure), 9th edition

Checked against references

This calculator includes 3 worked examples with independently sourced answers. They run in the test suite, and you can run them here too.

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