Before using this pressure result
- Identify whether the source reports gauge, absolute or differential pressure.
- Retain the instrument range and uncertainty, not just its displayed reading.
- Check whether a gas specification refers to operating pressure or standard reference conditions.
Keep the original pressure value, its unit and the relevant conditions in the record. A copied answer of 31.9083023006 psi is interpretable only when those details remain available. State which of the measurement checks above you verified before using the value in another calculation.
The reference behind the pressure
Pressure is force per unit area. This converter is useful for instrument readings, tyre specifications and technical documents using pascals, bars or psi. The unit alone does not reveal the pressure reference: gauge, absolute and differential readings require their reference information to remain attached.
A standard atmosphere is defined as 101,325 Pa, and one bar is 100,000 Pa. Psi means pound-force per square inch. Gauge pressure is measured relative to the local surrounding pressure, while absolute pressure is referenced to a vacuum. Changing a unit cannot supply the local atmospheric pressure needed to convert one reference to another.
Absolute pressure equals gauge pressure plus the relevant surrounding absolute pressure. That surrounding value is not automatically a standard atmosphere at every site. A differential pressure is a comparison between two specified points. Unit conversion preserves whichever reference was supplied; it cannot infer the reference or compensate for an unlabelled gauge.
Write the unit and reference together, such as gauge bar or absolute psi, and align the reference before comparing figures.
What this pressure comparison can tell you
Useful capabilities
Write the unit and reference together, such as gauge bar or absolute psi, and align the reference before comparing figures.
The listed units express the same supplied pressure quantity. The 2.2 bar → 31.9083023006 psi example makes the selected convention visible before it is used in a longer calculation.
Important limits
This converts units only; it does not convert gauge pressure to absolute pressure.
Add the relevant surrounding absolute pressure before comparing references. Use the exact named unit; their definitions differ.
| Possible mismatch | What resolves it |
|---|---|
| Equating gauge pressure with absolute pressure | Add the relevant surrounding absolute pressure before comparing references. |
| Treating bar and standard atmosphere as identical | Use the exact named unit; their definitions differ. |
Converting bar into psi preserves the pressure reference supplied by the source. Gauge-to-absolute conversion needs the relevant surrounding absolute pressure as another input. A standard atmosphere is a unit convention; it is not a measured ambient pressure for every site. Instrument accuracy may refer to full scale, so translate the specification using its stated basis rather than inferring it from the displayed digits.
As a controlled uncertainty example, suppose the original 2.2 bar record had a stated ±1% input interval. Its endpoints would be 2.178 bar and 2.222 bar. Converting those endpoints gives an output interval from 31.5892192776 psi to 32.2273853237 psi. The interval scales with the same fixed unit ratio as the central value. This chosen interval illustrates the arithmetic and is not an accuracy claim for your measurement.
A unit factor does not add atmospheric pressure
An instrument reads 2.2 bar and a specification uses psi. Before converting, check the pressure reference. A gauge reading is relative to its surroundings; an absolute reading is relative to vacuum. Two figures can share the same converted unit and still describe different pressures because their reference points differ.
A gauge pressure of 2.2 bar is approximately 31.9083 psi gauge. If the surrounding absolute pressure is assumed to be 1 bar for an illustration, the corresponding absolute pressure is 3.2 bar, approximately 46.4121 psi absolute. The extra 1 bar comes from the chosen reference assumption, not from converting bar into psi.
For an actual site, use the appropriate surrounding pressure rather than inserting the illustrative 1 bar without checking it. A standard atmosphere is 101,325 Pa by definition, but ambient atmospheric pressure need not equal that value. Altitude and weather can affect it. A label such as psig or psia may indicate the reference, while an unqualified psi label may require clarification.
Differential pressure is the difference between two specified points. Preserve the sign and identify which point is subtracted from which. A sensor's range and accuracy statement may refer to full scale rather than the instantaneous reading. Converting the central value alone does not translate that specification into a new performance claim. For equipment decisions, retain the device documentation and applicable pressure reference.
2.2 bar gauge plus an illustrative 1 bar ambient equals 3.2 bar absolute.
Pressure units, side by side
The values below all describe 2.2 bar. They provide a comparison of unit sizes for pressure; they are not separate measurements. Read the complete symbol and convention before copying a number.
- PaPascals
- 220,000 Pa
- kPaKilopascals
- 220 kPa
- MPaMegapascals
- 0.22 MPa
- barBars
- 2.2 bar
- psiPounds/square inch
- 31.9083023006 psi
- atmStandard atmospheres
- 2.17123118678 atm
- torrTorr
- 1,650.13570195 torr
Keep the original bars record alongside the converted pounds/square inch display. The unit list uses up to twelve significant digits for arithmetic readability, while the measurement precision still comes from its source.
Questions about pressure
Does this convert psig to psia?
No. It converts psi as a unit, retaining the supplied reference. Converting gauge to absolute pressure requires the surrounding pressure, which can vary with location and conditions.
Are torr and mmHg identical in every application?
This tool offers torr, defined using a standard atmosphere. A physical mercury-column reading can depend on gravity, temperature and the specified conventional definition. Do not silently replace one convention with another.
2.2 bar in pounds/square inch
2.2 bar = 31.9083023006 psi
Output = input × source factor ÷ destination factor2.2 × 100,000 ÷ 6,894.75729317 = 31.9083023006 psi. The two factors express the source and destination relative to the same internal reference unit. Their ratio is the multiplier.
Both unit factors refer to the same internal reference for pressure. Multiplying by the source factor and dividing by the destination factor changes the numerical scale while retaining the quantity. The source definition still matters: Add the relevant surrounding absolute pressure before comparing references.
Reversing the unrounded 31.9083023006 psi result returns 2.2 bar. Use this as a direction check. A consistent reverse calculation cannot resolve equating gauge pressure with absolute pressure or improve the original observation.
Label gauge, absolute or differential
When comparing a gauge data sheet and a system requirement, first align the pressure reference, then the unit. Keep both steps visible in the calculation record.
The following inputs stay in bars and the results use pounds/square inch. They illustrate different magnitudes for this measurement. Retain the specific conditions described above when replacing an example with your own value.
| Starting value | Equivalent value |
|---|---|
| 2.2 bar | 31.9083023006 psi |
| 3.2 bar | 46.4120760737 psi |
This pressure unit pair has a constant factor ratio. Changing the input changes the output by the same proportion. If a copied figure differs by an unexpected factor, review the full unit symbol before changing the source measurement. Use the exact named unit; their definitions differ.
Write the unit and reference together, such as gauge bar or absolute psi, and align the reference before comparing figures.