PSI to Bar Converter
Type a value in either field. The other side updates instantly using the exact ISO/NIST factor 1 PSI = 0.0689475729 bar.
PSI to Bar Conversion Reference Table
Common values you will hit in tire-pressure, hydraulic, scuba, and process service. Values are rounded to 4 decimals; for full precision use the calculator above.
| PSI | Bar | Typical use |
|---|---|---|
| 1 | 0.0689 | Reference unit |
| 10 | 0.6895 | Low water-line pressure |
| 14.5038 | 1.0000 | 1 bar (atmospheric reference) |
| 25 | 1.7237 | Tire pressure (typical light vehicle) |
| 30 | 2.0684 | Tire pressure (typical light truck) |
| 50 | 3.4474 | Garden-irrigation supply |
| 100 | 6.8948 | Industrial steam/water |
| 145.038 | 10 | 10 bar / process pressure |
| 300 | 20.684 | Scuba / SCBA tank charge |
| 500 | 34.474 | Hydraulic system (general) |
| 1000 | 68.948 | Hydraulic press / forge |
| 1450.38 | 100 | 100 bar / high-pressure hydraulic |
| 3000 | 206.84 | High-pressure hydraulic press |
| 5000 | 344.74 | Wellhead / extreme service |
PSI to Bar Formula
The conversion factor is exact and traceable to ISO 80000-4 and NIST SP 811. PSI (pound-force per square inch) is defined as 6,894.757293168 pascals; bar is defined as 100,000 pascals. The ratio gives 14.5037738 PSI per bar (exact to 7 decimals).
For most engineering work, four decimal places is enough. For metering-grade calibration certificates, use the full eight-decimal factor; for tire-pressure or quick mental math, 14.5 PSI ≈ 1 bar is good to within 0.3 percent.
Common Conversion Examples
Pressure ranges you actually encounter in the field:
PSI vs Bar — When Each Is Used
PSI dominates US-spec equipment (ASME, ANSI, SAE); bar dominates EU and most of the rest of the world (ISO, IEC). The split shows up most often when imported equipment lands on a domestic line: a 100-bar EU hydraulic press paired with a 1500-PSI US-spec gauge needs the same conversion you have here.
In pressure transmitter spec sheets, both units typically appear together; the gauge face shows the local convention while the data sheet lists the SI equivalent. ISO 80000-4 lists bar as a non-SI unit accepted for use with SI; NIST SP 811 does the same for PSI as a customary US unit.
In your own loop, pick whichever unit the operators on the floor read fastest. Mixing units mid-loop is the most common source of bad calibration readings we see in field reports.
Frequently Asked Questions
What is the formula to convert PSI to bar?
Multiply PSI by 0.0689475729 to get bar, or divide PSI by 14.5037738 to get the same answer. Both factors are exact within ISO 80000-4 / NIST SP 811.
Is 1 PSI equal to 1 bar?
No. 1 bar = 14.5037738 PSI, so they differ by a factor of about 14.5. People confuse them because both are everyday pressure units, but they are not equivalent.
How many PSI is in 1 bar?
1 bar = 14.5037738 PSI exactly. For most quick math, 1 bar is approximately 14.5 PSI, which is accurate to about 0.026 percent.
Why is bar used in Europe and PSI in the USA?
PSI is a customary US unit derived from pound-force and square-inch. Bar comes from the metric system; it equals 100,000 pascals. ISO and IEC standards lean on bar (alongside the pascal); ASME, ANSI, and SAE lean on PSI. Most spec sheets list both.
What is the difference between PSI, PSIA, and PSIG?
PSI is generic. PSIA is absolute (referenced to a sealed vacuum); PSIG is gauge (referenced to local atmospheric pressure). Bar follows the same pattern: bar(a) is absolute and bar(g) is gauge. When you convert, you keep the reference type unchanged: PSIG converts to bar(g), PSIA converts to bar(a).
Recommended HMK Products
All three units are available on the gauge face or transmitter display:
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