Unit Converters
Pressure Converter
Convert pressure units: PSI, bar, pascal, atmosphere, torr, mmHg, and more. Perfect for engineering, automotive, weather, diving, and scientific applications.
Use Pressure Converter to get instant results without uploads or sign-ups. Everything runs securely in your browser for fast, reliable output.
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About this tool
Pressure conversion is essential across many fields: automotive (tire pressure), meteorology (atmospheric pressure and weather), diving (water depth pressure), engineering (hydraulic systems), medicine (blood pressure), and aviation (altitude and cabin pressure). Different regions and industries use different pressure units, making conversions necessary for international communication, equipment specifications, and safety compliance.
Our Pressure Converter handles all common pressure units with precision. Convert between SI units (pascal, kilopascal, megapascal), imperial units (PSI - pounds per square inch), metric units (bar, millibar), atmospheric units (atm, torr, mmHg), and specialized units for various applications. The calculator uses exact conversion factors based on international standards.
Understanding pressure conversions helps in numerous situations: checking tire pressure with different gauges, interpreting weather maps from different countries, calculating diving depths and decompression, sizing hydraulic equipment, understanding medical blood pressure readings, and working with vacuum systems. For example, standard atmospheric pressure at sea level is about 14.7 PSI, 1 bar (actually 1.013 bar), or 760 mmHg.
The converter is valuable for automotive technicians checking tire pressure, meteorologists analyzing weather systems, divers planning safe descents, engineers designing pressure vessels, medical professionals monitoring blood pressure, and anyone working with compressed air or hydraulic systems. Accurate pressure conversions ensure safety, prevent equipment damage, and enable proper system operation across different measurement standards.
Usage examples
Tire Pressure
Convert 32 PSI to bar for European vehicles
32 PSI = 2.21 bar
Weather Pressure
Convert 1013 millibar to inches of mercury
1013 mbar = 29.92 inHg
Diving Depth
Convert 3 atmospheres to PSI
3 atm = 44.1 PSI
Blood Pressure
Convert 120 mmHg to kPa
120 mmHg = 16.0 kPa
Hydraulic System
Convert 3,000 PSI to megapascals
3,000 PSI = 20.68 MPa
How to use
- Enter the pressure value you want to convert.
- Select the unit you're converting FROM (e.g., PSI).
- Select the unit you're converting TO (e.g., bar).
- Click "Convert" to see the result instantly.
- The converter shows precise results for technical applications.
- Useful for tire pressure, weather forecasting, diving, and hydraulics.
Benefits
- Convert between all common pressure units instantly
- Accurate conversions using international standards
- Essential for automotive tire pressure checks
- Useful for weather forecasting and analysis
- Helps ensure diving safety with proper calculations
- Perfect for hydraulic and pneumatic system design
- Simplifies medical blood pressure interpretation
- Educational tool for physics and engineering students
- Free alternative to manual conversion calculations
- Prevents safety issues from incorrect pressure readings
- Mobile-friendly for field and shop use
- Supports both absolute and gauge pressure units
FAQs
What is the difference between PSI and bar?
PSI (pounds per square inch) is an imperial unit commonly used in the US, while bar is a metric unit used in most other countries. 1 bar = 14.504 PSI, and 1 PSI = 0.0689 bar. For tire pressure, 30 PSI is approximately 2.07 bar. European tire pressure specifications typically use bar.
How do I convert PSI to kPa?
Multiply PSI by 6.89476 to get kilopascals (kPa). For example, 30 PSI = 206.84 kPa. The kilopascal is commonly used in scientific and engineering contexts. Standard atmospheric pressure is about 14.7 PSI or 101.325 kPa.
What is atmospheric pressure and why does it matter?
Atmospheric pressure at sea level is approximately 14.7 PSI, 101.325 kPa, 1.013 bar, or 760 mmHg. This is considered "standard" or "1 atmosphere." It decreases with altitude, affecting engine performance, cooking times, and weather. Weather systems with high/low pressure create wind patterns and affect conditions.
What does gauge pressure vs absolute pressure mean?
Gauge pressure measures relative to atmospheric pressure (what most tire gauges show). Absolute pressure includes atmospheric pressure. If your tire gauge shows 32 PSI (gauge), the absolute pressure is about 46.7 PSI (32 + 14.7). In technical work, PSIG means gauge, PSIA means absolute.
How is mmHg used in blood pressure?
Blood pressure is measured in millimeters of mercury (mmHg). Normal blood pressure is about 120/80 mmHg (120 systolic, 80 diastolic). This unit comes from mercury manometers historically used. 1 mmHg = 0.133 kPa = 0.0193 PSI. It's also called "torr" in scientific contexts (1 mmHg ≈ 1 torr).
How deep can I dive at a given pressure?
Water pressure increases by approximately 1 atmosphere (14.7 PSI or 1 bar) every 10 meters (33 feet) of depth. At 20 meters depth, pressure is 3 atmospheres total (1 atmospheric + 2 from water). This affects air consumption, decompression needs, and equipment requirements. Always follow safe diving practices.
What tire pressure should I use?
Check your vehicle's door jamb sticker or owner's manual for recommended tire pressure, typically 30-35 PSI (2.1-2.4 bar) for passenger cars. The pressure molded into the tire sidewall is the MAXIMUM, not recommended. Adjust pressure when tires are cold, as driving heats them and increases pressure by 2-4 PSI.
Why do weather forecasts use different pressure units?
Weather services use various units: millibars or hectopascals (1 mbar = 1 hPa) are standard in meteorology worldwide, inches of mercury (inHg) in the US, and mmHg historically. Standard sea level pressure is 1013.25 mbar, 29.92 inHg, or 760 mmHg. High pressure (above 1020 mbar) often means fair weather; low pressure (below 1000 mbar) means storms.
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