How to Convert Pressure Units
Convert between different pressure units instantly. Our converter handles PSI, bar, pascal, atmospheres, and more-essential for automotive, HVAC, diving, and scientific applications.
Understanding Pressure Units
Pressure is force applied per unit area. Different industries use different units: PSI (pounds per square inch) in the US, bar in Europe, pascal (Pa) in science, and atmospheres (atm) for reference to sea-level air pressure.
Common Pressure Conversions
Key relationships: 1 atm = 101,325 Pa = 1.013 bar = 14.7 PSI. 1 bar = 100,000 Pa = 14.5 PSI. 1 PSI = 6,895 Pa.
Example:
Car tire pressure of 32 PSI = 32 × 0.069 = 2.2 bar. Atmospheric pressure is about 1 bar or 14.7 PSI.
Common Use Cases
Real-world applications for this calculator
Automotive
Convert tire pressure between PSI and bar, or understand engine specifications.
Scuba Diving
Calculate water pressure at depth and understand tank pressure ratings.
Weather
Understand barometric pressure readings in different units (millibars, inches of mercury).
Tips
- Quick conversion: PSI ÷ 14.5 ≈ bar, bar × 14.5 ≈ PSI.
- Tire gauges: some show both PSI and bar on dual scales.
- Atmospheric pressure drops about 12% per 1,000 meters of altitude.
Frequently Asked Questions
How do I convert PSI to bar?
Divide PSI by 14.5 to get bar. For example, 30 PSI = 30 ÷ 14.5 = 2.07 bar. For quick estimates, PSI ÷ 15 ≈ bar.
What is normal atmospheric pressure?
Standard atmospheric pressure at sea level is 1 atm = 101,325 Pa = 1.013 bar = 14.7 PSI = 760 mmHg. Weather reports often use millibars (1013.25 mbar at sea level).
What tire pressure should I use?
Check your vehicle's door jamb sticker for recommended PSI (typically 30-35 PSI for cars). European cars may specify bar (2.0-2.5 bar is common).
How does water pressure increase with depth?
Water pressure increases by about 1 atm (14.7 PSI) for every 10 meters (33 feet) of depth. At 30 meters, you experience about 4 atm total pressure.