Bars to Millibars (bar to mbar)
1 bar equals 1,000 millibars exactly.
How to convert bars to millibars
To convert bars to millibars, multiply the number of bars by 1,000. This factor is exact. To go the other way, multiply millibars by 0.001.
millibars = bars × 1,000
Example: 10 bars = 10,000 millibars.
About these units
Bar (bar)
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
Millibar (mbar)
One thousandth of a bar, equal to one hectopascal. Standard atmospheric pressure is 1,013.25 mbar.
Millibar and hectopascal are the same pressure with different pedigrees. The millibar was introduced alongside the bar by Vilhelm Bjerknes, and meteorologists worldwide adopted it because the values are convenient: a thousandth of a bar puts ordinary air pressure near 1,000. Standard atmospheric pressure is 1,013.25 millibars.
When SI came in, some meteorologists switched to hectopascals, which carry exactly the same numbers. The millibar did not vanish, though. The symbol mb is still common, and Americans know the unit from US hurricane and cyclone reports.
A few readings give the scale. The record-low non-tornadic pressure of 870 hPa in Typhoon Tip in 1979 equals 870 millibars, and falling pressure of about 12 hPa per 100 meters of altitude means a mountain road can shave tens of millibars off a barometer reading in a short climb.
1 millibar = 100 pascals (exactly).
Sources: Wikipedia: Bar (unit); Wikipedia: Hectopascal; Wikipedia: Atmospheric pressure
Related conversions
- Millibars to bars (reverse)
- Bars to pascals
- Bars to kilopascals
- Bars to standard atmospheres
- Bars to PSI
- Bars to hectopascals
- Bars to megapascals
- Bars to torr
- Bars to millimeters of mercury
- Bars to inches of mercury
- Bars to gigapascals
- Bars to kilopounds per square inch
- Bars to millimeters of water
- Pascals to millibars
- Kilopascals to millibars
- Standard atmospheres to millibars
- PSI to millibars
- Hectopascals to millibars
- Megapascals to millibars
- Torr to millibars
- Millimeters of mercury to millibars
- Inches of mercury to millibars
See all pressure units.