Megapascals to Bars (MPa to bar)

1 megapascal equals 10 bars exactly.

How to convert megapascals to bars

To convert megapascals to bars, multiply the number of megapascals by 10. This factor is exact. To go the other way, multiply bars by 0.1.

bars = megapascals × 10

Example: 10 megapascals = 100 bars.

About these units

Megapascal (MPa)

Metric (SI)Current unit

One million pascals. Used for material strength and hydraulic pressure.

Engineers reach for the megapascal because the pascal is far too small for solid materials. It is the preferred unit in engineering for stiffness and for tensile or compressive strength, and stiffness figures go on to gigapascals: aluminium is given as 69 GPa, structural steel as 200 GPa, and diamond as 1,220 GPa.

Fluid systems live in the same range. One megapascal is 10 bar, so scuba tanks filled to about 200 bar sit at 20 MPa, and fixed industrial hydraulic machinery commonly working at around 300 bar runs at about 30 MPa. A kilobar, used in experimental petrology, is 100 MPa.

For comparison with units from the pounds-and-inches world, one psi is about 6.895 kPa, so a megapascal is about 145 psi.

1 megapascal = 1,000,000 pascals (exactly).

Sources: Wikipedia: Pascal (unit); Wikipedia: Bar (unit); Wikipedia: Pounds per square inch

Bar (bar)

Metric (SI)Current unit

Exactly 100,000 pascals, close to atmospheric pressure at sea level. Used for tire pressure, diving and industrial gauges.

Bar began as a name that meant different things to different people. It comes from the Ancient Greek baros, weight, and from 1793 to 1795 an early metric system used bar for a unit of mass equal to the modern tonne. The pressure bar was introduced by the Norwegian meteorologist Vilhelm Bjerknes, a founder of modern weather forecasting, who defined it as one megadyne per square centimeter. Some earlier writers had used bar for one dyne per square centimeter, a source of confusion.

The bar is a metric unit but not part of the SI, and its official symbol is simply bar, since the old b clashes with the barn and the bit. It has been legally recognized in EU countries since 2004, although NIST deprecates it except for limited use in meteorology.

Its size is handy because 1 bar is slightly less than average sea-level pressure, which is about 1.013 bar. In scuba diving every 10 meters of seawater adds about 1 bar and a full standard tank holds about 200 bar. Tire pressure and turbocharger boost are often quoted in bar outside the US.

1 bar = 100,000 pascals (exactly).

Sources: Wikipedia: Bar (unit); Wikipedia: Atmospheric pressure

Related conversions

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