Pressure Converter
Welcome to the comprehensive pressure converter designed for converting between PSI, bar, pascal, atmospheres, mmHg, and all major pressure units. Perfect for engineers, HVAC technicians, physicists, medical professionals, and anyone working with pressure measurements across fluid mechanics, thermodynamics, and industrial applications.
Universal Pressure Converter
Convert Any Pressure Unit Instantly
Select your units and enter a value to convert between all major pressure measurements.
Conversion Result
Quick Conversions
Common Pressure Conversions
1 Bar
1 Atmosphere
1 PSI
1 Bar
Pressure Conversion Formulas
Pressure Definition
\[ P = \frac{F}{A} \]
Pressure equals force per unit area (Pa = N/m²)
PSI to Pascals
\[ \text{Pascals} = \text{PSI} \times 6,894.76 \]
Example: 50 PSI = 50 × 6,894.76 = 344,738 Pa
Bar to PSI
\[ \text{PSI} = \text{Bar} \times 14.5038 \]
Example: 3 bar = 3 × 14.5038 = 43.51 PSI
Understanding Pressure Units
Pascal (Pa)
The pascal is the SI unit of pressure, named after Blaise Pascal. One pascal equals one newton per square meter (N/m²). It's a small unit—atmospheric pressure is about 101,325 Pa. Commonly used with prefixes: kilopascal (kPa) for everyday pressures, megapascal (MPa) for high pressures in materials science and engineering.
PSI (Pounds per Square Inch)
PSI measures pressure as pounds-force per square inch, the standard unit in the United States for tire pressure, hydraulic systems, and compressed air. One PSI equals approximately 6,895 pascals. Common in automotive, pneumatic, and industrial applications. Tire pressures typically range from 30-35 PSI for passenger vehicles.
Bar
The bar is a metric unit approximately equal to atmospheric pressure at sea level. One bar equals exactly 100,000 pascals (100 kPa). Widely used in meteorology, engineering, and scuba diving. Weather maps show pressure in millibars (mbar). One bar is slightly less than one atmosphere (1 atm = 1.01325 bar).
Atmosphere (atm)
The standard atmosphere is defined as exactly 101,325 pascals, representing average atmospheric pressure at sea level. Used in chemistry, physics, and diving. One atmosphere equals 14.696 PSI or 1.01325 bar. Scuba diving depths are often expressed in atmospheres of pressure.
mmHg (Millimeters of Mercury)
Millimeters of mercury, also called torr, measures pressure by the height of a mercury column. Standard atmospheric pressure equals 760 mmHg. Commonly used in medicine for blood pressure (normal is 120/80 mmHg), vacuum measurements, and meteorology. One mmHg equals approximately 133.322 pascals.
Inches of Mercury (inHg)
Used primarily in aviation and weather reporting in the United States. Standard atmospheric pressure equals 29.92 inHg. Barometric pressure in weather forecasts is often given in inches of mercury. One inch of mercury equals approximately 3,386 pascals.
Comprehensive Conversion Tables
Common Pressure Units
| Unit | Pascals | PSI | Bar |
|---|---|---|---|
| 1 Pascal | 1 Pa | 0.000145 PSI | 0.00001 bar |
| 1 Kilopascal | 1,000 Pa | 0.145 PSI | 0.01 bar |
| 1 Bar | 100,000 Pa | 14.504 PSI | 1 bar |
| 1 PSI | 6,894.76 Pa | 1 PSI | 0.0689 bar |
| 1 Atmosphere | 101,325 Pa | 14.696 PSI | 1.013 bar |
Medical and Scientific Pressure
| Unit | Pascals | mmHg | PSI |
|---|---|---|---|
| 1 mmHg (Torr) | 133.322 Pa | 1 mmHg | 0.0193 PSI |
| 1 Inch Mercury | 3,386.39 Pa | 25.4 mmHg | 0.491 PSI |
| Standard Atmosphere | 101,325 Pa | 760 mmHg | 14.696 PSI |
| Normal Blood Pressure | 16,000 Pa | 120 mmHg | 2.32 PSI |
Hydraulic Pressure
| Description | PSI | Bar | MPa |
|---|---|---|---|
| Tire Pressure (Car) | 32 PSI | 2.2 bar | 0.22 MPa |
| Water Mains | 50-80 PSI | 3.4-5.5 bar | 0.34-0.55 MPa |
| Hydraulic Systems | 3,000 PSI | 207 bar | 20.7 MPa |
| Scuba Tank | 3,000 PSI | 207 bar | 20.7 MPa |
Practical Conversion Examples
Example 1: Tire Pressure
A tire pressure gauge reads 35 PSI. Convert to bar.
\[ 35 \text{ PSI} \times 0.0689476 = 2.413 \text{ bar} \]
Result: 35 PSI = 2.41 bar
Example 2: Atmospheric Pressure
Weather report shows 1013 mbar. Convert to PSI.
\[ 1013 \text{ mbar} = 1.013 \text{ bar} \times 14.5038 = 14.694 \text{ PSI} \]
Result: 1013 mbar = 14.69 PSI
Example 3: Blood Pressure
Blood pressure is 120 mmHg. Convert to kilopascals.
\[ 120 \text{ mmHg} \times 133.322 = 15,998.64 \text{ Pa} = 16.0 \text{ kPa} \]
Result: 120 mmHg = 16.0 kPa
Applications of Pressure Conversion
- Automotive Engineering: Converting tire pressures, engine specifications across PSI, bar, and kPa
- HVAC Systems: Refrigerant pressures, air conditioning specifications in multiple units
- Medical Field: Blood pressure measurements, respiratory therapy, hyperbaric chambers
- Aviation: Altimeter settings, cabin pressure, weather data in inches mercury
- Scuba Diving: Tank pressures, depth calculations, gas mix specifications
- Hydraulics: Industrial machinery, brake systems, fluid power calculations
- Meteorology: Weather forecasting, atmospheric pressure trends in various units
- Manufacturing: Vacuum systems, pressure vessels, quality control testing
Pressure Conversion Tips
- Absolute vs Gauge: Gauge pressure measures relative to atmospheric; absolute includes atmospheric
- Temperature Matters: Gas pressures vary with temperature—conversions assume constant temperature
- Know Your Context: Medical, industrial, and scientific fields may prefer different units
- Precision Requirements: Use exact conversion factors for critical applications
- Bar vs Atmosphere: One bar ≈ one atmosphere, but not exactly (1.01325 bar = 1 atm)
- Vacuum Pressure: Negative gauge pressure; absolute pressure is always positive
- Safety First: High-pressure systems require proper training and equipment
Common Pressure Questions
What is the difference between PSI and bar?
PSI (pounds per square inch) is an imperial unit commonly used in the United States, while bar is a metric unit used internationally. One bar equals approximately 14.5 PSI. Bar is roughly equivalent to atmospheric pressure at sea level, making it convenient for many applications. European tire pressures are typically specified in bar.
What is gauge pressure vs absolute pressure?
Gauge pressure measures pressure relative to atmospheric pressure (atmospheric = 0). Absolute pressure measures pressure relative to perfect vacuum. Absolute pressure = gauge pressure + atmospheric pressure. Most pressure gauges read gauge pressure, but scientific calculations often require absolute pressure.
How do you convert bar to PSI?
Multiply bar by 14.5038 to get PSI. For example, 2 bar × 14.5038 = 29.01 PSI. This conversion is essential when working with international equipment specifications or automotive tire pressures labeled in different systems.
Why Choose RevisionTown for Conversion Tools?
RevisionTown specializes in creating accurate, user-friendly calculators and educational resources for students, professionals, and anyone working with scientific and technical calculations. Our pressure converter is designed by expert educators who understand both the physics and practical applications across multiple disciplines.
Whether you're a student learning about fluid mechanics in IB, AP, GCSE, IGCSE curricula, an engineer specifying pressure systems, a technician working with hydraulics or HVAC, or anyone needing accurate pressure conversions, our calculator provides instant results with clear explanations.
Our commitment to educational excellence extends beyond simple conversion—we provide context, formulas, comprehensive tables, and practical understanding. The pressure converter exemplifies our approach: support for all major pressure units including SI, imperial, atmospheric, and medical measurements, clear mathematical formulas based on fundamental physics, extensive reference tables covering automotive, medical, industrial, and scientific applications, and tools that serve genuine needs in engineering, healthcare, and professional work.
Disclaimer: This pressure converter is provided for educational and general purposes. While we strive for maximum accuracy using internationally standardized conversion factors, results should be verified for critical applications such as pressure vessel design, medical equipment, or safety systems. Pressure measurements may be gauge or absolute—verify which is required for your application. For professional engineering, medical, or safety-critical applications, consult authoritative references and verify all conversions. Values used: 1 bar = 100,000 Pa exactly, 1 PSI = 6,894.757 Pa, 1 atm = 101,325 Pa exactly, 1 mmHg = 133.322 Pa.
Complete list of pressure units for conversion
- pascal [Pa]
- 1 kilopascal [kPa] = 1000 pascal [Pa]kilopascal to pascal, pascal to kilopascal
- 1 bar = 100000 pascal [Pa]bar to pascal, pascal to bar
- 1 psi [psi] = 6894.7572931783 pascal [Pa]psi to pascal, pascal to psi
- 1 ksi [ksi] = 6894757.2931783 pascal [Pa]ksi to pascal, pascal to ksi
- 1 Standard atmosphere [atm] = 101325 pascal [Pa]Standard atmosphere to pascal, pascal to Standard atmosphere
- 1 exapascal [EPa] = 1.0E+18 pascal [Pa]exapascal to pascal, pascal to exapascal
- 1 petapascal [PPa] = 1.0E+15 pascal [Pa]petapascal to pascal, pascal to petapascal
- 1 terapascal [TPa] = 1000000000000 pascal [Pa]terapascal to pascal, pascal to terapascal
- 1 gigapascal [GPa] = 1000000000 pascal [Pa]gigapascal to pascal, pascal to gigapascal
- 1 megapascal [MPa] = 1000000 pascal [Pa]megapascal to pascal, pascal to megapascal
- 1 hectopascal [hPa] = 100 pascal [Pa]hectopascal to pascal, pascal to hectopascal
- 1 dekapascal [daPa] = 10 pascal [Pa]dekapascal to pascal, pascal to dekapascal
- 1 decipascal [dPa] = 0.1 pascal [Pa]decipascal to pascal, pascal to decipascal
- 1 centipascal [cPa] = 0.01 pascal [Pa]centipascal to pascal, pascal to centipascal
- 1 millipascal [mPa] = 0.001 pascal [Pa]millipascal to pascal, pascal to millipascal
- 1 micropascal [µPa] = 1.0E-6 pascal [Pa]micropascal to pascal, pascal to micropascal
- 1 nanopascal [nPa] = 1.0E-9 pascal [Pa]nanopascal to pascal, pascal to nanopascal
- 1 picopascal [pPa] = 1.0E-12 pascal [Pa]picopascal to pascal, pascal to picopascal
- 1 femtopascal [fPa] = 1.0E-15 pascal [Pa]femtopascal to pascal, pascal to femtopascal
- 1 attopascal [aPa] = 1.0E-18 pascal [Pa]attopascal to pascal, pascal to attopascal
- 1 newton/square meter = 1 pascal [Pa]newton/square meter to pascal, pascal to newton/square meter
- 1 newton/square centimeter = 10000 pascal [Pa]newton/square centimeter to pascal, pascal to newton/square centimeter
- 1 newton/square millimeter = 1000000 pascal [Pa]newton/square millimeter to pascal, pascal to newton/square millimeter
- 1 kilonewton/square meter = 1000 pascal [Pa]kilonewton/square meter to pascal, pascal to kilonewton/square meter
- 1 millibar [mbar] = 100 pascal [Pa]millibar to pascal, pascal to millibar
- 1 microbar [µbar] = 0.1 pascal [Pa]microbar to pascal, pascal to microbar
- 1 dyne/square centimeter = 0.1 pascal [Pa]dyne/square centimeter to pascal, pascal to dyne/square centimeter
- 1 kilogram-force/square meter = 9.80665 pascal [Pa]kilogram-force/square meter to pascal, pascal to kilogram-force/square meter
- 1 kilogram-force/sq. cm = 98066.5 pascal [Pa]kilogram-force/sq. cm to pascal, pascal to kilogram-force/sq. cm
- 1 kilogram-force/sq. millimeter = 9806650 pascal [Pa]kilogram-force/sq. millimeter to pascal, pascal to kilogram-force/sq. millimeter
- 1 gram-force/sq. centimeter = 98.0665 pascal [Pa]gram-force/sq. centimeter to pascal, pascal to gram-force/sq. centimeter
- 1 ton-force (short)/sq. foot = 95760.517960678 pascal [Pa]ton-force (short)/sq. foot to pascal, pascal to ton-force (short)/sq. foot
- 1 ton-force (short)/sq. inch = 13789514.586338 pascal [Pa]ton-force (short)/sq. inch to pascal, pascal to ton-force (short)/sq. inch
- 1 ton-force (long)/square foot = 107251.78011595 pascal [Pa]ton-force (long)/square foot to pascal, pascal to ton-force (long)/square foot
- 1 ton-force (long)/square inch = 15444256.336697 pascal [Pa]ton-force (long)/square inch to pascal, pascal to ton-force (long)/square inch
- 1 kip-force/square inch = 6894757.2931783 pascal [Pa]kip-force/square inch to pascal, pascal to kip-force/square inch
- 1 pound-force/square foot = 47.8802589804 pascal [Pa]pound-force/square foot to pascal, pascal to pound-force/square foot
- 1 pound-force/square inch = 6894.7572931783 pascal [Pa]pound-force/square inch to pascal, pascal to pound-force/square inch
- 1 poundal/square foot = 1.4881639436 pascal [Pa]poundal/square foot to pascal, pascal to poundal/square foot
- 1 torr [Torr] = 133.3223684211 pascal [Pa]torr to pascal, pascal to torr
- 1 centimeter mercury (0°C) = 1333.22 pascal [Pa]centimeter mercury (0°C) to pascal, pascal to centimeter mercury (0°C)
- 1 millimeter mercury (0°C) = 133.322 pascal [Pa]millimeter mercury (0°C) to pascal, pascal to millimeter mercury (0°C)
- 1 inch mercury (32°F) [inHg] = 3386.38 pascal [Pa]inch mercury (32°F) to pascal, pascal to inch mercury (32°F)
- 1 inch mercury (60°F) [inHg] = 3376.85 pascal [Pa]inch mercury (60°F) to pascal, pascal to inch mercury (60°F)
- 1 centimeter water (4°C) = 98.0638 pascal [Pa]centimeter water (4°C) to pascal, pascal to centimeter water (4°C)
- 1 millimeter water (4°C) = 9.80638 pascal [Pa]millimeter water (4°C) to pascal, pascal to millimeter water (4°C)
- 1 inch water (4°C) [inAq] = 249.082 pascal [Pa]inch water (4°C) to pascal, pascal to inch water (4°C)
- 1 foot water (4°C) [ftAq] = 2988.98 pascal [Pa]foot water (4°C) to pascal, pascal to foot water (4°C)
- 1 inch water (60°F) [inAq] = 248.843 pascal [Pa]inch water (60°F) to pascal, pascal to inch water (60°F)
- 1 foot water (60°F) [ftAq] = 2986.116 pascal [Pa]foot water (60°F) to pascal, pascal to foot water (60°F)
- 1 atmosphere technical [at] = 98066.500000003 pascal [Pa]atmosphere technical to pascal, pascal to atmosphere technical
