PSI to PSIG
Convert an absolute-style pressure input into PSIG by subtracting atmospheric pressure.
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PSI to PSIG Table (14.696 psi Atmosphere)
| Input Pressure | Atmospheric PSI | PSIG |
|---|---|---|
| 15 | 14.696 | 0.304 |
| 20 | 14.696 | 5.304 |
| 25 | 14.696 | 10.304 |
| 40 | 14.696 | 25.304 |
| 60 | 14.696 | 45.304 |
| 80 | 14.696 | 65.304 |
| 100 | 14.696 | 85.304 |
| 150 | 14.696 | 135.304 |
| 200 | 14.696 | 185.304 |
| 500 | 14.696 | 485.304 |
Popular Conversions
- 15 input pressure = 0.304 psig at 14.696 psi atmosphere
- 20 input pressure = 5.304 psig at 14.696 psi atmosphere
- 25 input pressure = 10.304 psig at 14.696 psi atmosphere
- 40 input pressure = 25.304 psig at 14.696 psi atmosphere
- 60 input pressure = 45.304 psig at 14.696 psi atmosphere
- 80 input pressure = 65.304 psig at 14.696 psi atmosphere
- 100 input pressure = 85.304 psig at 14.696 psi atmosphere
- 150 input pressure = 135.304 psig at 14.696 psi atmosphere
What is PSI and PSIG?
PSI
Definition: PSI means pounds per square inch and is a customary pressure unit.
History/origin: It became a standard engineering and industrial unit in US customary practice.
Current use: PSI is used in hydraulics, pneumatics, tires, compressors, and pressure gauges.
PSIG
Definition: PSIG means pounds per square inch gauge and measures pressure relative to ambient atmosphere.
History/origin: Gauge notation grew with dial gauges and plant instruments that read above local atmospheric pressure.
Current use: PSIG is used in shop air, hydraulics, tanks, and most everyday pressure gauges.
Related Hydraulic Conversions
Hydraulic and water-system work often mixes pressure, head, force, and flow estimates in the same check.
| Related Conversion | Factor or Rule | Formula |
|---|---|---|
| psi to feet of water | × 2.306658726 | ft H2O = psi × 2.306658726 |
| psi to inches of water | × 27.67990472 | in H2O = psi × 27.67990472 |
| psi to head | water assumption | head(ft) = psi × 2.306658726 |
| psi to gpm | needs Cv and SG | Q = Cv × sqrt(DeltaP / SG) |
| psi to lbs | needs area | lb = psi × area(in^2) |
| Pa to psi | × 0.000145037738 | psi = Pa × 0.000145037738 |
| psia to psig | minus atmosphere | psig = psia – atmospheric pressure |
| psig to psia | plus atmosphere | psia = psig + atmospheric pressure |
Typical Use Cases
Frequently Asked Questions
Q: Why is atmospheric pressure part of this conversion?
A: Gauge pressure removes the atmospheric baseline, so the converter subtracts the atmospheric reference from the absolute-style value.
Q: What default atmosphere does the converter use?
A: The default is 14.696 psi, a common sea-level reference. You can change it if your workflow needs another value.
Q: What is the difference between PSIA and PSIG?
A: PSIA includes atmosphere, while PSIG shows only the pressure above local atmospheric conditions.
Q: Can the result be negative?
A: Yes. If the input absolute pressure is below the atmospheric reference, the resulting gauge pressure is negative.
Q: Why does the table use 14.696 psi?
A: That reference keeps the pattern easy to scan. The live field above lets you use another atmospheric value when needed.
Q: When is this useful?
A: It is useful in vacuum systems, gas-law calculations, compressors, and any job that must move between absolute and gauge notation.