Pressure units used in engineering, weather, tires, vacuum, medicine and fluid columns.
All factors come from the central conversion registry.
| Unit | Symbol | System | Definition |
|---|---|---|---|
| Pascal | Pa | SI | 1 Pa = 1 N/m² |
| Kilopascal | kPa | SI | 1 kPa = 1000 Pa |
| Hectopascal | hPa | SI | 1 hPa = 100 Pa |
| Megapascal | MPa | SI | 1 MPa = 10⁶ Pa |
| Gigapascal | GPa | SI | 1 GPa = 10⁹ Pa |
| Bar | bar | Metric | 1 bar = exactly 100,000 Pa |
| Millibar | mbar | Metric | 1 mbar = 100 Pa |
| Barye | Ba | CGS | 1 Ba = 0.1 Pa |
| Pounds per Square Inch | psi | US customary | 1 psi ≈ 6894.757293168 Pa |
| Standard Atmosphere | atm | Standard | 1 atm = exactly 101325 Pa |
| Technical Atmosphere | at | Metric gravitational | 1 at = exactly 98,066.5 Pa |
| Torr | Torr | Vacuum | 1 Torr = 101325/760 Pa |
| Millimeters of Mercury | mmHg | Medical | 1 mmHg ≈ 133.322387415 Pa |
| Centimeters of Mercury | cmHg | Conventional | 1 cmHg ≈ 1,333.22387415 Pa |
| Inches of Mercury | inHg | Aviation/Weather | 1 inHg ≈ 3386.389 Pa |
| Inches of Water | inH₂O | Conventional | 1 inH₂O ≈ 249.08891 Pa |
Pressure expresses force per unit area. Pascals, kilopascals, bar, atmospheres and psi are kept in one dimension so incompatible units cannot be mixed accidentally.
The interactive calculator, reference table and indexed pair pages all read from the same conversion registry, so unit definitions and formulas stay synchronized.
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