From pascals (Pa)
- Pascals to KilopascalsPa → kPa
- Pascals to BarPa → bar
- Pascals to Pounds-force per square inchPa → psi
- Pascals to Standard atmospheresPa → atm
Pressure conversion family
Pressure unit conversions
Pressure is force divided by area and has dimension M L⁻¹ T⁻²; the coherent SI unit is the pascal (Pa), equal to N/m².
Five named units
Unit and factor reference
| Unit | Symbol | Factor to base | Relationship | Definition and variant |
|---|---|---|---|---|
| pascal | Pa | 1 | defined | The pascal is the coherent SI unit of pressure and stress: 1 Pa = 1 N/m² = 1 kg·m⁻¹·s⁻². The base factor is exactly 1 by the family base-unit choice. |
| kilopascal | kPa | 1000 | exact | A kilopascal is the SI decimal multiple formed with kilo: 1 kPa = 1000 Pa. The decimal-prefix relationship is exact. |
| bar | bar | 100000 | defined | The bar is a non-SI pressure unit defined as 0.1 MPa or exactly 100,000 Pa. Named variant: Pressure unit bar; not the unrelated typographic or musical word. The relationship to the pascal is exact. |
| pound-force per square inch | psi | 6894.757293 | approximate | Psi in this family is pound-force per square international inch (lbf/in²). With standard gravity it is approximately 6894.75729316836 Pa. Named variant: Pound-force per square inch using standard gravity; not pound-mass per square inch. Gauge versus absolute reference must be specified separately. The preserved baseFactor 6894.757293 Pa is rounded from about 6894.75729316836 Pa, a difference of about 1.68×10⁻⁷ Pa per psi. |
| standard atmosphere | atm | 101325 | defined | The standard atmosphere is defined as exactly 101,325 Pa. Named variant: Standard atmosphere (atm); not technical atmosphere (at) or a measured local atmospheric pressure. The relationship to the pascal is exact. |
Every ordered pair
All 20 pressure calculators
From kilopascals (kPa)
- Kilopascals to PascalskPa → Pa
- Kilopascals to BarkPa → bar
- Kilopascals to Pounds-force per square inchkPa → psi
- Kilopascals to Standard atmosphereskPa → atm
From bar (bar)
- Bar to Pascalsbar → Pa
- Bar to Kilopascalsbar → kPa
- Bar to Pounds-force per square inchbar → psi
- Bar to Standard atmospheresbar → atm
From pounds-force per square inch (psi)
From standard atmospheres (atm)
Evidence and review status
This family is machine-reviewed-pending-human. Automated checks verify structure, factor parity and source references; they do not constitute human or specialist approval.
Family assumptions and limits
- This family converts non-negative pressure magnitudes only. It does not add or subtract atmospheric reference pressure when changing between absolute, gauge, differential, or vacuum readings.
- Input and output must refer to the same pressure reference and measurement conditions; a unit conversion alone cannot change the reference datum.
- Psi means pound-force per square inch (lbf/in²) using standard gravity, not pound-mass per square inch.
Authoritative references
- The International System of Units (SI), 9th edition, version 4.01; Bureau International des Poids et Mesures; Section 2.3.4, Table 4, p. 133: pressure/stress use pascal Pa = kg·m⁻¹·s⁻² = N/m²; Section 3, Table 7, p. 138 (kilo); Section 4, Table 8, p. 140: 1 bar = 10⁵ Pa.; accessed 2026-08-07
- NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically; National Institute of Standards and Technology; Entries 'atmosphere, standard', 'bar', and 'pound-force per square inch (psi)'/'psi'; footnote 23 gives the exact pound-force factor when standard gravity g_n = 9.80665 m/s² is used.; accessed 2026-08-07
- NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement; National Institute of Standards and Technology; Page C-20, Units of Pressure: Pa, kPa, MPa, and pound-force per square inch (psi, lbf/in²) table; page C-21 gives the international-inch basis for U.S. customary equivalents.; accessed 2026-08-07