MPa to psi converter, megapascals in pounds per square inch.

To convert MPa to psi, multiply by 145.038. So 1 MPa is 145.038 psi, 10 MPa is 1,450.4 psi and 0.5 MPa is 72.52 psi. One megapascal is 1,000,000 pascals, which is 10 bar, and a psi is 6,894.757 pascals.

How to use the converter

1. Type the amount in the Megapascals (MPa) box. A decimal such as 2.5 or a fraction such as 3/4 works.
2. The big result shows Pounds per square inch (psi). Use Decimals in the side column to fix the number of places.
3. The cards under the result give the same pressure in other units.
4. Type in the second box, or press the swap button, to convert pounds per square inch to megapascals instead.
5. Click a row in Common values to load it. Copy result, Copy link, Copy table and Print chart keep the answer. Start again resets the box.

The factor, worked out

1,000,000 ÷ 6,894.757293 = 145.037738. NIST prints the pound-force per square inch as 6.894 757 E+03 Pa. The converter derives the exact value from the pound, standard gravity and the inch.

Strength numbers

Material strength is often quoted in MPa, because a pascal is tiny. A value of 250 MPa is 36,259 psi. In US papers that is written as 36 ksi, because 1 ksi is 1,000 psi. Check the powers of ten when you move between the two.

MPa to psi, a table

Worked examples

• A pipe rated 1.6 MPa. 232.1 psi, or 16 bar.
• A 20 MPa hydraulic circuit. 2,901 psi.
• A 0.4 MPa supply. 58 psi.
• Back the other way. 3,000 psi = 20.684 MPa. Press the swap button and type 3000.

Powers of ten with pressure

Pressure units run in steps of 1,000: pascal, kilopascal, megapascal. Psi sits near the kilopascal in size, since 1 psi is 6.9 kPa. So 1 MPa, which is 1,000 kPa, is about 145 psi. To check an answer, divide the MPa figure by 0.0069: 0.7 ÷ 0.0069 is about 101, and the exact answer is 101.5 psi. Leaving out a power of ten is the usual error with MPa.

Gauge or absolute pressure

A tyre gauge, a pressure washer dial and most boiler gauges show gauge pressure, which is the pressure above the air around them. Absolute pressure counts from a perfect vacuum, so it is the gauge reading plus the air pressure. At one standard atmosphere, 101.325 kPa, 1 MPa gauge is 1.101325 MPa absolute. The Gauge or absolute box above the tables does the sum in either direction. Air pressure changes with weather and height, so one standard atmosphere is only an average. The standard atmosphere is from NIST SP 811 Appendix B.8, checked 24 Oct 2026.

Where the numbers come from

NIST SP 811, Appendix B.8 lists the pound-force per square inch as 6.894 757 E+03 Pa; the megapascal itself is 1,000,000 Pa by the SI prefix. Checked 24 Oct 2026. The converter keeps the factors as exact fractions and rounds only the last digit shown. It is a unit converter, not a safety tool: for a tyre, boiler or tank, use the value printed on the equipment or in its manual.

Related pages: Psi to bar, Psi to kPa, Bar to psi and Unit converter.