Pressure Calculator
The Pressure Calculator converts between different pressure units including kPa, psi, bar, mmHg, and atmospheres. Essential for engineering, scientific, and HVAC applications.
Understanding Pressure Units
Pressure is force per unit area and is measured in various units depending on the application and region. Understanding pressure conversions is essential for engineering, scientific, and HVAC applications.
Common Pressure Units
Pascal (Pa) and Kilopascal (kPa)
- Definition: SI base unit, 1 Pa = 1 N/m²
- Usage: Scientific calculations, international standards
- Scale: 1 kPa = 1000 Pa
- Typical Values: Atmospheric pressure ≈ 101.325 kPa
Pounds per Square Inch (psi)
- Definition: Force in pounds applied over one square inch
- Usage: United States, automotive, industrial
- Variants: psig (gauge), psia (absolute)
- Typical Values: Atmospheric pressure ≈ 14.7 psi
Bar and Millibar
- Definition: 1 bar = 100,000 Pa = 100 kPa
- Usage: Meteorology, European industry
- Scale: 1 bar = 1000 mbar
- Typical Values: Atmospheric pressure ≈ 1.013 bar
Atmosphere (atm)
- Definition: Standard atmospheric pressure at sea level
- Value: 1 atm = 101.325 kPa exactly
- Usage: Chemistry, physics, diving
- Reference: Historical standard pressure
Conversion Factors
| From | To | Multiply by |
|---|---|---|
| kPa | psi | 0.145038 |
| kPa | bar | 0.01 |
| kPa | atm | 0.00986923 |
| kPa | mmHg | 7.50062 |
| psi | kPa | 6.89476 |
Applications by Field
HVAC and Building Systems
- Static Pressure: Fan and duct system design
- Refrigeration: System pressures and safety
- Boilers: Steam pressure monitoring
- Pneumatic Controls: Control system pressures
Industrial Applications
- Process Control: Reactor and vessel pressures
- Hydraulics: Fluid power systems
- Pneumatics: Compressed air systems
- Safety Systems: Pressure relief and monitoring
Scientific and Laboratory
- Vacuum Systems: Low pressure measurements
- Gas Analysis: Partial pressure calculations
- Material Testing: Pressure testing protocols
- Calibration: Pressure standard references
Reference Pressures
| Condition | kPa | psi | bar |
|---|---|---|---|
| Perfect Vacuum | 0 | 0 | 0 |
| Standard Atmosphere | 101.325 | 14.696 | 1.013 |
| Typical Car Tire | 220 | 32 | 2.2 |
| Scuba Tank | 20,700 | 3,000 | 207 |
Note: Pressure conversions are exact mathematical relationships. Always verify the pressure type (absolute vs. gauge) and consider measurement uncertainty for critical applications.