Pressure Converter
Convert pressure and stress measurements between SI metric units (Pascals, bar), traditional Imperial units (pounds per square inch / psi), and barometric standards (atmospheres, torr / mmHg).
1 bar = 14.503774 psi
1 bar = 14.503774 psi
Common Conversions
1 bar =100,000 Pa
1 bar =100 kPa
1 bar =0.1 MPa
1 bar =0.9869 atm
1 bar =14.5038 psi
How Pressure Conversions Work
Pressure is defined as perpendicular force applied per unit area (P = F / A). The coherent International System of Units (SI) unit of pressure is the Pascal (Pa), defined as one Newton of force distributed evenly over one square meter (1 N/m²).
1 Pascal (Pa) = 1 N/m²
1 Kilopascal (kPa) = 1,000 Pa
1 Megapascal (MPa) = 1,000,000 Pa = 10 bar
1 Bar = 100,000 Pa (exactly 10&sup5; Pa)
1 Standard Atmosphere (atm) = 101,325 Pa
1 Torr (mmHg) = 101,325 / 760 ≈ 133.322 Pa
1 Pound per Square Inch (psi) ≈ 6,894.757 Pa
Gauge Pressure vs. Absolute Pressure
When working with pressure measurements, it is essential to know whether your reading is absolute or gauge:
- Absolute Pressure (psia, bara): Measured relative to a perfect vacuum (zero pressure). Used in thermodynamic calculations, physics, and meteorology.
- Gauge Pressure (psig, barg): Measured relative to ambient atmospheric pressure (approx. 14.696 psi or 1.013 bar at sea level). A tire gauge reading of 32 psi indicates pressure 32 psi above ambient air (approx. 46.7 psi absolute).
* Note: Unit conversion ratios convert identical numerical deltas regardless of reference plane, but absolute offsets must be accounted for when mixing gauge and absolute measurements.
Official Pressure Conversion Factors
| Unit | Symbol | System | Exact Definition in Pascals (Pa) |
|---|---|---|---|
| Pascal | Pa | SI Base Equivalent | 1 Pa (1 N/m²) |
| Kilopascal | kPa | Metric SI Prefix | 1,000 Pa (10³ Pa) |
| Megapascal | MPa | Metric SI Prefix | 1,000,000 Pa (10&sup6; Pa = 1 N/mm²) |
| Bar | bar | Metric / Industry | 100,000 Pa (10&sup5; Pa) |
| Standard Atmosphere | atm | International Standard | 101,325 Pa (Standard sea-level air) |
| Pound per Square Inch | psi | US Customary / Imperial | 6,894.757293168 Pa |
| Torr (mmHg) | Torr | Barometric / Vacuum | 101,325 / 760 ≈ 133.322368 Pa |
Common Everyday Pressure Conversions
Vehicle Tire Inflation
32 psi ≈ 2.21 bar (220.6 kPa)
Standard Sea Level Air
1 atm = 101.325 kPa = 14.696 psi
Scuba Diving Tank
200 bar ≈ 2,900 psi (20 MPa)
Espresso Machine
9 bar ≈ 130.5 psi (900 kPa)
Barometric Vacuum
1 Torr = 1 mmHg ≈ 133.32 Pa
Residential Water Main
50 psi ≈ 3.45 bar (344.7 kPa)