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Convert Pounds per Square Inch to Gigapascals

Instantly convert Pounds per Square Inch (psi) to Gigapascals (GPa) with our free online calculator.

Reviewed by Christopher FloiedUpdated

Formula: psi to GPamultiply by 6.8948e-6

Reference Table

Pounds per Square Inch (psi)Gigapascals (GPa)
10.00000689476
50.0000344738
100.0000689476
250.000172369
500.000344738
1000.000689476

How to Convert Pounds per Square Inch to Gigapascals

Formula

To convert Pounds per Square Inch (psi) to Gigapascals (GPa): multiply by 6.8948e-6

Step-by-Step

  1. Start with your value in Pounds per Square Inch (psi).
  2. Multiply by 6.8948e-6 to perform the conversion.
  3. The result is your value expressed in Gigapascals (GPa).

Conversion Factor

1 psi = 0.00000689476 GPa

Reverse Factor

1 GPa = 145038 psi

Worked Example

Convert 25 Pounds per Square Inch to Gigapascals: 25 psi = 0.000172369 GPa

About Pound per Square Inch (psi)

An imperial unit of pressure equal to one pound-force applied over one square inch (exactly 6,894.757 Pa per NIST SP 811). PSI is the dominant US pressure unit and remains the working unit in most US-built industrial, automotive, and consumer equipment: passenger-car tire inflation (32-35 psi cold), compressed air shop systems (typically 100-150 psi), hydraulic equipment (1,500-3,000 psi mobile, up to 10,000 psi on press brakes), ammunition chamber pressures (SAAMI specs in psi), municipal potable water supply (~40-80 psi at the meter), and natural gas distribution pressures. US engineering textbooks and the ASME B31 pipe codes, API piping specifications, and AWWA waterworks standards quote allowable pressures in psi. Engineers should distinguish gauge psi (psig — pressure above atmospheric) from absolute psi (psia — pressure above perfect vacuum); 0 psig = 14.696 psia at sea level. 1 psi = 6.895 kPa = 0.0689 bar = 51.715 mmHg.

About Gigapascal (GPa)

A metric unit of pressure equal to exactly 1,000,000,000 pascals (1,000 MPa). Gigapascals are the standard unit for reporting elastic-modulus and material-stiffness properties — Young's modulus of structural steel is ~200-210 GPa, aluminum alloys ~69-72 GPa, titanium ~110 GPa, concrete ~25-35 GPa, single-crystal diamond ~1,050-1,200 GPa, and CFRP composite ~150-230 GPa (longitudinal). MatWeb, NIST's MMP database, and the ASM Handbook tabulate elastic constants in GPa. GPa is also the working unit for ultra-high-pressure scientific experiments: diamond-anvil cell measurements (currently extending past 1,000 GPa = 1 TPa for studies of metallic hydrogen and Earth-core conditions), shock-wave equation-of-state research at national labs (LANL, LLNL, Sandia), and geophysics interior models — Earth's outer core lies between roughly 135 and 330 GPa. 1 GPa = 10,000 bar = 145,038 psi.

Quick Facts

  • 1 Pound per Square Inch equals 0.00000689476 Gigapascals
  • 1 Gigapascal equals 145038 Pounds per Square Inch
  • Pound per Square Inch is a unit of pressure
  • Gigapascal is a unit of pressure
  • This conversion is commonly used in tire inflation, weather reporting, scuba diving, and engineering
  • The Pound per Square Inch belongs to the imperial system
  • The Gigapascal belongs to the metric system

Common Pound per Square Inch to Gigapascal Conversions

Pounds per Square Inch (psi)Gigapascals (GPa)
0.16.894757e-7
0.50.00000344738
10.00000689476
20.0000137895
50.0000344738
100.0000689476
14.6960.000101325
150.000103421
200.000137895
250.000172369
500.000344738
1000.000689476
1500.00103421
2000.00137895
5000.00344738
10000.00689476

Understanding Pounds per Square Inch

The Pound per Square Inch (symbol: psi) is a unit of pressure. An imperial unit of pressure equal to one pound-force applied over one square inch (exactly 6,894.757 Pa per NIST SP 811). PSI is the dominant US pressure unit and remains the working unit in most US-built industrial, automotive, and consumer equipment: passenger-car tire inflation (32-35 psi cold), compressed air shop systems (typically 100-150 psi), hydraulic equipment (1,500-3,000 psi mobile, up to 10,000 psi on press brakes), ammunition chamber pressures (SAAMI specs in psi), municipal potable water supply (~40-80 psi at the meter), and natural gas distribution pressures. US engineering textbooks and the ASME B31 pipe codes, API piping specifications, and AWWA waterworks standards quote allowable pressures in psi. Engineers should distinguish gauge psi (psig — pressure above atmospheric) from absolute psi (psia — pressure above perfect vacuum); 0 psig = 14.696 psia at sea level. 1 psi = 6.895 kPa = 0.0689 bar = 51.715 mmHg.

It belongs to the imperial measurement system.

Pounds per Square Inch are commonly used in tire inflation, weather reporting, scuba diving, and engineering.

Understanding Gigapascals

The Gigapascal (symbol: GPa) is a unit of pressure. A metric unit of pressure equal to exactly 1,000,000,000 pascals (1,000 MPa). Gigapascals are the standard unit for reporting elastic-modulus and material-stiffness properties — Young's modulus of structural steel is ~200-210 GPa, aluminum alloys ~69-72 GPa, titanium ~110 GPa, concrete ~25-35 GPa, single-crystal diamond ~1,050-1,200 GPa, and CFRP composite ~150-230 GPa (longitudinal). MatWeb, NIST's MMP database, and the ASM Handbook tabulate elastic constants in GPa. GPa is also the working unit for ultra-high-pressure scientific experiments: diamond-anvil cell measurements (currently extending past 1,000 GPa = 1 TPa for studies of metallic hydrogen and Earth-core conditions), shock-wave equation-of-state research at national labs (LANL, LLNL, Sandia), and geophysics interior models — Earth's outer core lies between roughly 135 and 330 GPa. 1 GPa = 10,000 bar = 145,038 psi.

It belongs to the metric measurement system.

Gigapascals are commonly used in tire inflation, weather reporting, scuba diving, and engineering.

Why Convert Pounds per Square Inch to Gigapascals?

Engineers, mechanics, and scientists frequently need to convert pressure between Pounds per Square Inch and Gigapascals when working with different measurement standards. Tire pressure, blood pressure readings, weather barometric measurements, and industrial process specifications may all use different pressure units depending on the region or discipline. Reliable conversion prevents equipment misuse and ensures safety.

Frequently Asked Questions

How do I convert Pounds per Square Inch to Gigapascals?

An imperial unit of pressure equal to one pound-force applied over one square inch (exactly 6,894. To convert Pounds per Square Inch to Gigapascals, multiply by 6.8948e-6. For example, 25 psi equals 0.000172369 GPa.

How many Gigapascals are in 1 Pound per Square Inch?

There are 0.00000689476 Gigapascals in 1 Pound per Square Inch.

How many Pounds per Square Inch are in 1 Gigapascal?

There are 145038 Pounds per Square Inch in 1 Gigapascal.

What is the formula for Pound per Square Inch to Gigapascal conversion?

The formula is: multiply by 6.8948e-6. This means 1 psi = 0.00000689476 GPa.

Is a Pound per Square Inch bigger than a Gigapascal?

Yes. One Pound per Square Inch is larger than one Gigapascal because 1 psi equals 0.00000689476 GPa, which is less than 1.

When do you need to convert between Pounds per Square Inch and Gigapascals?

A metric unit of pressure equal to exactly 1,000,000,000 pascals (1,000 MPa). Pound per Square Inch and Gigapascal are both pressure units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.

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