MPa Conversion Calculator
Enter a pressure value in any unit - megapascals, psi, bar, kPa, Pa, atm, Torr, inHg or N/mm2 - and every other unit updates instantly. The calculator works in both directions: type in MPa to get psi or bar, or type psi to get MPa. Conversion factors are anchored to the SI pascal definition so results are exact.
What is a megapascal (MPa)?
A megapascal is one million pascals (1 MPa = 1,000,000 Pa). The pascal is the SI unit of pressure, defined as one newton of force acting on one square metre of area (1 Pa = 1 N/m2). Because a single pascal is very small for most engineering applications, the megapascal is the standard working unit in hydraulics, structural engineering and materials testing. One notable identity: 1 MPa equals exactly 1 N/mm2, which means concrete compressive strength, steel yield strength and similar structural figures can be quoted in either unit without any arithmetic.
How to convert MPa to other pressure units
Every conversion goes through the SI chain. Multiply the MPa value by 1,000,000 to get pascals, then divide by the pa-per-unit factor for the target. In practice the most-used shortcuts are: MPa x 10 = bar, MPa x 1,000 = kPa, MPa x 145.038 = psi, MPa x 9.8692 = atm, MPa x 7,500.62 = Torr. Reversing the direction, divide by those same factors to convert from psi, bar or kPa back to MPa. This calculator does both automatically: choose your source unit, enter a value, and all nine target units update at once.
Gauge, absolute and differential pressure
A pressure reading can be gauge (psig, barg - relative to local atmospheric), absolute (psia, bara - relative to a perfect vacuum) or differential (the difference between two points). Conversion factors between units are the same for all three reference types; what changes is the reference baseline. Standard atmospheric pressure is 0.101325 MPa (101,325 Pa, 1.01325 bar, 14.696 psi, 1 atm). To convert gauge to absolute, add 0.101325 MPa to the gauge reading. This calculator converts units only - it does not add or subtract the atmospheric offset, so make sure your input and output reference types are consistent.
Common MPa values across industries
City water mains typically run at 0.1 to 0.5 MPa (15 to 73 psi). Car tyres are inflated to roughly 0.22 to 0.35 MPa (32 to 51 psi). Hydraulic excavator circuits operate at 20 to 35 MPa (2,900 to 5,000 psi). Normal concrete has a compressive strength of 20 to 40 MPa, structural steel yields at around 250 MPa. Deep-sea environments reach roughly 100 MPa per 10 km of depth. Aircraft cabin differential pressure is around 0.06 MPa (8.7 psi). High-pressure water cutting jets can exceed 400 MPa (58,000 psi).
Pressure unit conversion factors (relative to 1 MPa)
| Unit | Symbol | 1 MPa equals | Typical application |
|---|---|---|---|
| Pascal | Pa | 1,000,000 | SI base unit, scientific |
| Kilopascal | kPa | 1,000 | General engineering, tyre pressure |
| Bar | bar | 10 | European industry, meteorology |
| Millibar | mbar | 10,000 | Meteorology, weather maps |
| Pounds per square inch | psi | 145.0377 | US industry, hydraulics |
| Standard atmosphere | atm | 9.8692 | Reference pressure, diving |
| Torr (mmHg) | Torr | 7,500.62 | Vacuum systems, medical |
| Inches of mercury | inHg | 295.30 | Barometric, aviation altimetry |
| Newton per sq. millimetre | N/mm2 | 1 | Structural engineering, concrete |
All factors are exact or rounded to the precision of the SI definition. 1 MPa = 1,000,000 Pa by definition.
Frequently asked questions
How do I convert MPa to psi?
Multiply the MPa value by 145.0377. For example, 10 MPa x 145.0377 = 1,450.4 psi. To reverse the calculation, divide psi by 145.0377 to get MPa. This factor comes from the exact SI definition: 1 psi = 6,894.757293 Pa, so 1 MPa / 6,894.757293 Pa/psi = 145.0377 psi.
How do I convert MPa to bar?
Multiply by 10: 1 MPa = 10 bar. This is the simplest conversion in pressure work. The bar is defined as exactly 100,000 Pa, and 1 MPa is 1,000,000 Pa, so the ratio is exactly 10. To go from bar to MPa, divide by 10.
What is the difference between MPa and N/mm2?
There is no difference numerically: 1 MPa = 1 N/mm2 exactly. The reason is dimensional analysis: 1 Pa = 1 N/m2, and 1 m2 = 1,000,000 mm2, so 1,000,000 Pa = 1,000,000 N/m2 = 1 N/mm2. Structural engineers and materials testers often write N/mm2 because the physical picture of force per area is more intuitive, while scientists prefer MPa as the SI-consistent form.
How do I convert MPa to kPa?
Multiply by 1,000: 1 MPa = 1,000 kPa. The kilo- prefix means one thousand, and mega- means one million, so the ratio between them is always 1,000. Conversely, divide kPa by 1,000 to get MPa.
What is 1 MPa in atm?
One MPa equals approximately 9.8692 standard atmospheres. Standard atmosphere is defined as exactly 101,325 Pa, and 1 MPa is 1,000,000 Pa, so 1,000,000 / 101,325 = 9.8692 atm. Most industrial pressures are expressed in MPa rather than atm because the numbers are more compact.
How do I convert MPa to Torr or mmHg?
Multiply by 7,500.6168: 1 MPa = 7,500.6168 Torr. Torr and mmHg are effectively equal for most practical purposes (they differ by less than 0.000002%). The Torr is defined as exactly 101,325/760 Pa, and 1 MPa / (101,325/760) Pa/Torr = 7,500.62 Torr. Torr and mmHg are common in vacuum systems and medical applications such as blood pressure measurement.
What pressure is typical for hydraulic systems in MPa?
Light hydraulics such as power steering circuits run at 5 to 15 MPa (725 to 2,175 psi). Industrial hydraulic presses and excavators typically operate at 20 to 35 MPa (2,900 to 5,075 psi). High-performance hydraulic systems and some aircraft systems can reach 70 MPa (10,000 psi). Ultra-high-pressure water cutting jets exceed 400 MPa (58,000 psi).