Convert Pound per Square Inch to Megapascal (psi → MPa)
PSI (pounds per square inch) is the standard for American tire pressures, hydraulics, and gas-cylinder specifications.
Pound per Square Inch to Megapascal Conversion Table
10 common values| Pound per Square Inch | Megapascal |
|---|---|
| 1 psi | 0.006895 MPa |
| 5 psi | 0.034474 MPa |
| 10 psi | 0.068948 MPa |
| 25 psi | 0.172369 MPa |
| 50 psi | 0.344738 MPa |
| 100 psi | 0.689476 MPa |
| 200 psi | 1.378952 MPa |
| 500 psi | 3.447379 MPa |
| 1,000 psi | 6.894757 MPa |
| 5,000 psi | 34.473786 MPa |
How to Convert Pound per Square Inch to Megapascal Manually
Step by StepConverting psi to megapascals is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.
- 1Take your value in psiStart with the number of psi (psi) you want to convert.
- 2Multiply by 0.006895The conversion factor from psi to MPa is 0.006895. Multiply your value by this number.
- 3Read the result in megapascalsThe result is your value in megapascals (MPa).
Formula
Multiply the value in psi by 0.006895. For the reverse direction, multiply by 145.03774.
MPa = psi × 0.006895psi = MPa × 145.03774Tips
Use these in everyday conversions- 1 psi ≈ 6.9 kPa = 0.069 bar.
- 14.7 psi = 1 atm = 1.01 bar.
- Most US pressure gauges show psi.
Common Mistakes
Avoid these- Setting a European tyre at 35 bar instead of 35 psi — disaster.
- Confusing psi (gauge) with psia (absolute).
- Using psi in scientific papers — prefer Pa or MPa.
About Pound per Square Inch and Megapascal
What is the Pound per Square Inch?
Pounds per square inch (psi) equals approximately 6,895 pascals and is the standard pressure unit in American tire pressures, hydraulics, and gas-cylinder specifications. American car tires are typically inflated to 30–35 psi, household water systems run at 40–60 psi, and scuba tanks are filled to 3,000 psi (about 200 bar). The psi is essential in American engineering for stress calculations, hydraulic systems, and pneumatic equipment. Two variants exist: 'psig' (gauge, measured above atmospheric) and 'psia' (absolute, including atmosphere) — gauge is the default unless specified. The psi relates to the pascal (1 psi ≈ 6,895 Pa), the kilopascal (1 psi ≈ 6.895 kPa), the bar (14.504 psi = 1 bar), the atmosphere (14.696 psi = 1 atm), and the inch of mercury (1 inHg ≈ 0.491 psi). Outside the US, kPa or bar dominate.
- US tyre pressures
- US plumbing and water system specs
- US compressed-air tool ratings
US tyre: 32–35 psi. Water supply: 40–60 psi. SCUBA tank: 3000 psi. Car AC system: 30–200 psi.
What is the Megapascal?
The megapascal equals 1,000,000 pascals (or 10 bar) and is the engineering high-pressure unit used in hydraulics, materials testing, and construction. Concrete compressive strength is rated in MPa (typical residential concrete is 20–35 MPa, structural concrete 35–70 MPa, high-strength up to 140 MPa), and steel yield strengths are 250–700 MPa for structural grades. Hydraulic systems operate at 10–70 MPa, and high-pressure-water-jet cutting reaches 400 MPa. The megapascal is dimensionally identical to N/mm² (newtons per square millimeter), making it natural for engineering calculations involving small areas. Earth's mantle pressure reaches gigapascals (1 GPa = 1,000 MPa). The MPa relates to the pascal (10⁶ Pa = 1 MPa), the bar (10 bar = 1 MPa), the psi (1 MPa ≈ 145.04 psi), and the atmosphere (1 MPa ≈ 9.87 atm). It is the standard unit in modern engineering specifications worldwide.
- Hydraulic system pressures
- Concrete and steel strength specifications
- High-pressure industrial processes
Concrete compressive strength: 20–60 MPa. Hydraulic press: 30–70 MPa. Steel yield strength: 250+ MPa.