MPa to PSIG Conversion
Convert megapascals (MPa) to pounds per square inch gauge (PSIG) instantly with this free online pressure converter. Formula: PSIG = (MPa × 145.038) - 14.7. Ideal for engineering, hydraulics, HVAC, and industrial applications.
About This Calculator
This MPa to PSIG Conversion Calculator is a free online tool that converts pressure values from megapascals (MPa) to pounds per square inch gauge (PSIG). It is designed for engineers, hydraulic and pneumatic technicians, materials scientists, and anyone who needs accurate pressure conversions between SI and imperial gauge pressure units.
The conversion uses the standard formula: PSIG = (MPa × 145.038) - 14.7. First, the MPa value is multiplied by 145.038 to convert to pounds per square inch (PSI), then 14.7 psi (standard atmospheric pressure at sea level) is subtracted to obtain gauge pressure. Gauge pressure measures pressure relative to the surrounding atmosphere, which is what most pressure gauges and sensors display. Since 1 MPa = 10 bar = 1,000,000 Pa, the conversion factor of 145.038 is derived from dividing 1,000,000 Pa by 6,894.76 Pa per PSI.
Why convert MPa to PSIG?
MPa (megapascal) is the SI standard unit for pressure and is widely used in engineering, materials science, and industrial applications worldwide. PSIG (pounds per square inch gauge) is the standard gauge pressure unit in the United States for hydraulic systems, pneumatic equipment, pressure vessels, and industrial processes. Converting between these units is essential for international equipment specifications, cross-border engineering projects, and understanding pressure ratings on equipment from different manufacturers. Many high-pressure applications, such as hydraulic presses (typically 20-35 MPa / 2,900-5,076 PSIG) and material testing equipment, specify pressures in MPa while their US counterparts use PSIG.
Regional Notes
India: MPa is the standard unit for pressure in engineering and construction following the SI system as per IS codes. Industrial equipment and hydraulic systems specify pressure ratings in MPa, while older equipment and automotive applications may still reference kg/cm² or PSI.
United States: PSIG is the dominant unit for most pressure measurements including hydraulic systems, pneumatic tools, pressure vessels, and industrial gauges. MPa is encountered on imported equipment, scientific instruments, and in international standards documentation.
United Kingdom: MPa is widely used in engineering, materials science, and industrial contexts, following EU and international standards. PSIG is still common on older equipment and in some specialized trade fields. Many UK industrial gauges display both MPa and PSI scales.
Common applications
- Hydraulic system pressure ratings (typically 14-35 MPa / 2,030-5,076 PSIG)
- Material tensile and yield strength specifications
- High-pressure autoclaves and pressure vessels
- Oil and gas wellhead and pipeline pressures
- Aerospace hydraulic and pneumatic systems
- Industrial compressed air systems at high pressures
Frequently Asked Questions
What is the formula to convert MPa to PSIG?
The formula to convert MPa to PSIG is: PSIG = (MPa × 145.038) - 14.7. First multiply the MPa value by 145.038 to get PSI, then subtract 14.7 (standard atmospheric pressure at sea level) to obtain gauge pressure.
What is the difference between PSI and PSIG?
PSI (pounds per square inch) measures absolute pressure relative to a perfect vacuum, while PSIG (pounds per square inch gauge) measures pressure relative to atmospheric pressure (14.7 psi at sea level). PSIG = PSI - 14.7. Gauge pressure is what most pressure gauges and tire pressure readings display.
How many PSIG is 1 MPa?
1 MPa equals approximately 130.34 PSIG at sea level. This is because 1 MPa = 145.038 PSI, and subtracting atmospheric pressure (14.7 psi) gives roughly 130.34 PSIG. MPa is commonly used for high-pressure industrial and engineering applications.
How do I convert 6 MPa to PSIG?
To convert 6 MPa to PSIG: multiply 6 by 145.038 to get 870.228 PSI, then subtract 14.7 to get 855.528 PSIG. So 6 MPa is approximately 855.53 PSIG. This pressure is typical for high-pressure hydraulic systems.
Can MPa to PSIG conversion be used for tire pressure?
Tire pressure is typically measured in bar or PSI rather than MPa, since 1 MPa equals about 145 PSI — much higher than typical tire pressures (0.2-0.35 MPa or 30-50 PSIG). MPa to PSIG conversion is more commonly used for industrial hydraulics, high-pressure equipment, and engineering applications.
Is MPa to PSIG conversion accurate for all altitudes?
The standard formula subtracts 14.7 psi for sea-level atmospheric pressure. At higher altitudes, atmospheric pressure is lower, so the actual PSIG reading would be slightly higher than the formula calculates. For most practical applications at typical elevations, the sea-level formula provides sufficient accuracy.
What industries use MPa to PSIG conversion?
MPa to PSIG conversion is widely used in hydraulic engineering (press ratings up to 35 MPa), materials testing (tensile and yield strength in MPa), oil and gas (wellhead and pipeline pressures), high-pressure autoclaves and pressure vessels, and aerospace hydraulic systems where pressures commonly range from 14 to 35 MPa.
How do I convert PSIG back to MPa?
To convert PSIG back to MPa, first add 14.7 to the PSIG value to get PSIA, then divide by 145.038. For example, 855.53 PSIG: (855.53 + 14.7) ÷ 145.038 = 6 MPa. Our calculator supports reverse conversion naturally.