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Convert Pounds per Square Inch to Megapascals

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

Reviewed by Christopher FloiedUpdated

Formula: psi to MPamultiply by 0.00689476

Reference Table

Pounds per Square Inch (psi)Megapascals (MPa)
10.00689476
50.0344738
100.0689476
250.172369
500.344738
1000.689476

How to Convert Pounds per Square Inch to Megapascals

Formula

To convert Pounds per Square Inch (psi) to Megapascals (MPa): multiply by 0.00689476

Step-by-Step

  1. Start with your value in Pounds per Square Inch (psi).
  2. Multiply by 0.00689476 to perform the conversion.
  3. The result is your value expressed in Megapascals (MPa).

Conversion Factor

1 psi = 0.00689476 MPa

Reverse Factor

1 MPa = 145.038 psi

Worked Example

Convert 25 Pounds per Square Inch to Megapascals: 25 psi = 0.172369 MPa

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 Megapascal (MPa)

A metric unit of pressure equal to exactly 1,000,000 pascals (1,000 kPa), or 10 bar. Megapascals are the universal SI unit for material strength reporting in structural and mechanical engineering: concrete compressive strength (typically 20-60 MPa per ACI 318 / Eurocode 2, with ultra-high-performance concrete reaching 150-200 MPa), structural-steel yield stress (250 MPa for S275 / A36, 355 MPa for S355, up to 690 MPa for HSLA grades), aluminum tensile (6061-T6 ~310 MPa), and the fracture toughness of ceramics and polymers reported as MPa·m^½ in materials databases. Mechanical-engineering finite-element solvers (Abaqus, ANSYS, Nastran), pressure-vessel codes (ASME BPVC Section VIII, PD 5500, EN 13445), hydraulic system specifications above ~70 bar, and the civil-engineering concrete mix specs all use MPa as the working pressure/stress unit. Common conversions: 1 MPa = 10 bar = 145.04 psi = 9.869 atm.

Quick Facts

  • 1 Pound per Square Inch equals 0.00689476 Megapascals
  • 1 Megapascal equals 145.038 Pounds per Square Inch
  • Pound per Square Inch is a unit of pressure
  • Megapascal 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 Megapascal belongs to the metric system

Common Pound per Square Inch to Megapascal Conversions

Pounds per Square Inch (psi)Megapascals (MPa)
0.10.000689476
0.50.00344738
10.00689476
20.0137895
50.0344738
100.0689476
14.6960.101325
150.103421
200.137895
250.172369
500.344738
1000.689476
1501.03421
2001.37895
5003.44738
10006.89476

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 Megapascals

The Megapascal (symbol: MPa) is a unit of pressure. A metric unit of pressure equal to exactly 1,000,000 pascals (1,000 kPa), or 10 bar. Megapascals are the universal SI unit for material strength reporting in structural and mechanical engineering: concrete compressive strength (typically 20-60 MPa per ACI 318 / Eurocode 2, with ultra-high-performance concrete reaching 150-200 MPa), structural-steel yield stress (250 MPa for S275 / A36, 355 MPa for S355, up to 690 MPa for HSLA grades), aluminum tensile (6061-T6 ~310 MPa), and the fracture toughness of ceramics and polymers reported as MPa·m^½ in materials databases. Mechanical-engineering finite-element solvers (Abaqus, ANSYS, Nastran), pressure-vessel codes (ASME BPVC Section VIII, PD 5500, EN 13445), hydraulic system specifications above ~70 bar, and the civil-engineering concrete mix specs all use MPa as the working pressure/stress unit. Common conversions: 1 MPa = 10 bar = 145.04 psi = 9.869 atm.

It belongs to the metric measurement system.

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

Why Convert Pounds per Square Inch to Megapascals?

Engineers, mechanics, and scientists frequently need to convert pressure between Pounds per Square Inch and Megapascals 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 Megapascals?

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 Megapascals, multiply by 0.00689476. For example, 25 psi equals 0.172369 MPa.

How many Megapascals are in 1 Pound per Square Inch?

There are 0.00689476 Megapascals in 1 Pound per Square Inch.

How many Pounds per Square Inch are in 1 Megapascal?

There are 145.038 Pounds per Square Inch in 1 Megapascal.

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

The formula is: multiply by 0.00689476. This means 1 psi = 0.00689476 MPa.

Is a Pound per Square Inch bigger than a Megapascal?

Yes. One Pound per Square Inch is larger than one Megapascal because 1 psi equals 0.00689476 MPa, which is less than 1.

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

A metric unit of pressure equal to exactly 1,000,000 pascals (1,000 kPa), or 10 bar. Pound per Square Inch and Megapascal 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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