Bar to Psig Conversion Calculator - bar(g) to psig in One Step

A bar to psig conversion turns a gauge pressure reading in bar into pounds per square inch gauge (psig), and back, in a single step. It uses the fixed relationship that 1 bar equals exactly 100,000 pascals and 1 psi equals exactly 6,894.757293168 pascals, so 1 bar(g) equals 14.5037738 psig. The 'g' suffix on both sides means both readings sit on the same reference: a gauge that reads zero at standard atmospheric pressure.

• • Tire pressure and road gauges: Move between bar(g) on European tire placards and the psig values on North American tire gauges for 2.2 bar car tires, 2.5–3.0 bar bicycle tires, and 4.0+ bar motorcycle tires.
• • SCUBA and compressed-gas cylinders: Translate a 200 bar(g) or 300 bar(g) fill into the psig rating on a regulator or compressor spec sheet without losing precision.
• • Hydraulic and pneumatic systems: Convert pump, compressor, and actuator ratings between bar(g) and psig for installation manuals and OEM cross-references.
• • Process and leak-test pressures: Use the same 14.5037738 factor on leak-test hold pressures and pneumatic line set-points when a European datasheet quotes bar(g) and the workflow expects psig.

The bar is a metric pressure unit defined by ISO 80000-4 as exactly 100,000 pascals, and the pound per square inch is a US customary unit defined by NIST as exactly 6,894.757293168 pascals. Both bar(g) and psig read zero at standard atmospheric pressure, so the 14.5037738 psig per bar(g) ratio is exact.

When the source or destination drops the 'g' suffix and treats the reading as plain psi, the Bar to PSI Conversion uses the same 14.5037738 factor without the explicit gauge reference.

The conversion is a single exact ratio built from the NIST definition of the two units, with the same gauge reference on both sides. Multiplying a bar(g) value by 14.5037738 gives the psig value, and dividing a psig value by 14.5037738 gives the bar(g) value.

• p(bar(g)): Pressure in bar(g) above atmospheric pressure (gauge reading)
• p(psig): Pressure in psig above atmospheric pressure (gauge reading)
• direction: Toggle that picks bar(g) → psig or psig → bar(g) so the same tool handles both directions

The same bar(g) value is converted into kPa(g) (× 100) and into standard atmospheres by adding the 1.01325 bar standard atmosphere, so the absolute cross-check rows read from the same underlying gauge reading.

According to NIST SP 811 (Guide for the Use of SI), 1 bar equals exactly 100,000 pascals and 1 psi equals exactly 6,894.757293168 pascals, which makes the bar(g) to psig ratio 100,000 ÷ 6,894.757293168 = 14.5037738 psig per bar(g)

For the atm-side panel that also covers bar, kPa, and psi in one entry, the Bar to ATM Conversion Calculator reads the same bar value against the full pressure family.

Four ideas explain why a bar to psig conversion works the way it does: an exact ISO 80000-4 factor for the bar(g), an exact NIST factor for the psi, the shared gauge reference, and the way psia, kPa(g), and atm sit on top of the same reading.

When the workflow needs to compare bar(g) and psig against atm, torr, mmHg, and Pa in one entry, a Pressure Converter sits next to the bar to psig conversion as the cross-unit overview.

The bar to psig conversion calculator has a value field and a direction toggle. Pick the direction, type the gauge reading, and read the converted gauge pressure plus the psia, kPa(g), and atm absolute cross-check rows in the same result panel.

1. 1 Pick the conversion direction: Use the dropdown to switch between Bar gauge (bar(g)) to Pound per square inch gauge (psig) and Pound per square inch gauge (psig) to Bar gauge (bar(g)). The default is bar(g) → psig for the most common workflow.
2. 2 Type the gauge reading: Enter the value in the unit set by the direction toggle. Try 1 for a sanity check, 2.2 for a car tire, 200 for a SCUBA tank fill, or 4.0 for a high-pressure bicycle tire.
3. 3 Read the converted gauge pressure: The black box at the top of the result panel shows the answer in the target gauge unit. For 1 bar(g), the answer is 14.5037738 psig; for 14.5037738 psig, the answer is 1 bar(g). The unit label switches with the direction toggle.
4. 4 Cross-check the psia, kPa(g), and atm rows: The result panel also shows the same pressure in psia (gauge plus 14.696 psi atmosphere), in kPa(g) (bar(g) × 100), and in standard atmospheres. Compare against a published chart to confirm the factor and the reference are being applied correctly.
5. 5 Switch direction for the reverse: Toggle the direction dropdown to flip between bar(g) → psig and psig → bar(g). The same value and cross-check rows are kept, so a round trip takes two clicks and never loses precision.

A tire placard on a European car lists 2.2 bar(g) front and 2.0 bar(g) rear. Toggle the direction to bar(g) → psig and type 2.2. The calculator returns 31.9083024 psig with cross-check rows of 29.1997738 psia (after adding 14.696 psi atmosphere), 220 kPa(g), and 1.98692 atm absolute. Toggle to psig → bar(g) and the same 31.9083024 psig rounds back to 2.2 bar(g).

For weather and altimeter work where the natural unit is the millibar or hectopascal rather than the psig, the Barometric Pressure Conversion Calculator applies the same 1.01325 bar sea-level standard against mmHg and inHg.

The advantage of a single, factor-driven bar to psig conversion is that the result is exact, the cross-check rows are reference-aware, and the same tool handles both directions without losing precision.

• • Exact NIST factor: The 1 bar(g) = 14.5037738 psig ratio is fixed by the NIST pascal definitions, so the calculator returns the same value at any precision with no empirical calibration needed.
• • Bidirectional in one tool: Switch the direction toggle to flip between bar(g) → psig and psig → bar(g). The same input and cross-check rows stay in place, so a round-trip never loses precision.
• • Reference-aware cross-check rows: Every result includes the same pressure in psia, kPa(g), and atm absolute, so a 1 bar(g) tire reading of 29.1997738 psia and 1.98692 atm sits next to its 14.5037738 psig value.
• • Worked tire and SCUBA examples: The 1 bar(g) reference, the 2.2 bar(g) car tire, and the 300 bar(g) SCUBA tank are built into the explanation, covering tire placards, regulator specs, and high-pressure cylinder work.

For a broader psi-side panel that also covers kPa, bar, atm, and MPa, the PSI Conversion Calculator applies the same NIST pascal definitions to the full psi family.

The bar(g) to psig unit factor is exact, but the usefulness of any specific number depends on what the input represents, on the precision of the original reading, and on whether the source, the converter, and the destination all use the same gauge reference.

• • The bar is not an SI unit, even though it is accepted for use alongside the SI by the BIPM. Always check the unit the rest of the system expects.
• • The conversion factor is exact, but the real pressure being measured is not. A tire pressure of 2.2 bar(g) is a single cold-inflation snapshot, and the actual pressure rises by roughly 0.2 bar(g) at operating temperature.

For a quick sanity check, atmospheric pressure is the most useful benchmark. At 1.01325 bar(a), the atmosphere reads 14.696 psia, the same number that anchors US weather reports, altimeter settings, and SCUBA tank ratings.

According to ISO 80000-4:2019, the bar is a non-SI unit accepted for use with the SI and is defined as exactly 100,000 pascals, while the standard atmosphere is exactly 101,325 pascals, which is the source value used in the bar to psig reference conversion

For the pascal-side anchor that also covers atm, kPa, mbar, and bar, the ATM to Pascals Conversion reads the same number against the full SI prefix ladder.