Bar to PSIG Conversion Calculator — Bar to Gauge Pressure in PSI
Convert absolute pressure in bar to gauge pressure in psig (psi gauge). PSIG measures pressure above the local atmospheric reference — useful for tyres, pipelines and hydraulic systems.
bar
psi
Pressure above atmospheric reference — negative means sub-atmospheric (vacuum side)
- 1
Bar to absolute psi
2 × 14.5038 = 29.00751 bar = 100,000 Pa ÷ 6,894.757 Pa/psi ≈ 14.5038 psi (absolute). - 2
Subtract atmospheric reference
29.0075 − 14.6959 = 14.3116
How does this calculator work?
psig = bar × 14.5038 − 14.6959. Because 1 bar (100,000 Pa) is slightly less than 1 atm (101,325 Pa), 1 bar absolute ≈ −0.192 psig. At 1.01325 bar (= 1 atm) gauge reads 0. For bar gauge to psig, just multiply by 14.5038 directly — the atmospheric offset cancels.
Formula
How this is calculated
Gauge pressure (psig) measures how far a pressure is above the local atmospheric pressure, rather than above a perfect vacuum. An inflated tyre at "32 psig" is 32 psi above atmospheric — the tyre has a higher absolute pressure of roughly 32 + 14.696 = 46.696 psia.
The conversion from bar to psig has two steps: first convert bar to absolute psi (psia = bar × 14.5038), then subtract the atmospheric reference (default 14.6959 psi = 1 standard atm). Because 1 bar = 100,000 Pa < 1 atm = 101,325 Pa, a pressure of exactly 1 bar (absolute) is slightly sub-atmospheric in gauge terms: 1 bar ≈ 14.5038 − 14.696 ≈ −0.192 psig. A pressure of 1.01325 bar (= 1 atm) corresponds to 0 psig.
The atmospheric reference is editable — if local barometric pressure differs from standard (e.g. at altitude or with weather variation), enter the measured atmospheric pressure in psi to get the correct local gauge reading. For tyre and industrial pressure gauges calibrated at sea level, the default 14.696 psi is appropriate.
Frequently asked questions
1 bar = 100,000 Pa, which is slightly less than 1 standard atmosphere (101,325 Pa ≈ 14.696 psi). So 1 bar absolute corresponds to about −0.192 psig — just below atmospheric. 1 atm absolute = 0 psig by definition.
If your bar reading is already gauge (bar g), the conversion is the same multiplication factor as absolute: psig ≈ bar_gauge × 14.5038. This works because the atmospheric offset cancels: (P_abs_bar × 14.5038 − P_atm_psi) = (P_gauge_bar × 14.5038), since P_atm in bar × 14.5038 = P_atm in psi.
Use psig when specifying pressures above atmospheric — tyre inflation, gas cylinder regulators, hydraulic systems, and plumbing. Use psia or bar (absolute) in thermodynamics, compressibility calculations, or when the absolute quantity matters (e.g. Boyle's law: PV = nRT requires absolute pressure).
TG we-Calculate Editorial Team. (2026). Bar to PSIG Conversion Calculator — Bar to Gauge Pressure in PSI [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/bar-to-psig-conversion-calculator
TG we-Calculate Editorial Team. "Bar to PSIG Conversion Calculator — Bar to Gauge Pressure in PSI." TG we-Calculate. 2026. https://we-calculate.com/calculator/bar-to-psig-conversion-calculator.
TG we-Calculate Editorial Team, "Bar to PSIG Conversion Calculator — Bar to Gauge Pressure in PSI," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/bar-to-psig-conversion-calculator
@misc{wecalculate_bar_to_psig_conversion_calculator, title = {Bar to PSIG Conversion Calculator — Bar to Gauge Pressure in PSI}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/bar-to-psig-conversion-calculator}}, year = {2026}, note = {TG we-Calculate} }
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