Millibars to bar
Multiply millibars by 0.001 to get bar.
1,013 mbar = 1.013 bar
How to convert millibars to bar
The bar is exactly 100 000 pascals (100 kPa), close to one atmosphere. The millibar is exactly 100 pascals (one hectopascal), one thousandth of a bar — the weather-pressure unit.
Worked example — 1,013 mbar: 1,013 × 0.001 = 1.013 bar.
Millibars to bar table
| Millibars | Bar |
|---|---|
| 100 mbar | 0.1 bar |
| 500 mbar | 0.5 bar |
| 900 mbar | 0.9 bar |
| 1,000 mbar | 1 bar |
| 1,013 mbar | 1.013 bar |
| 1,050 mbar | 1.05 bar |
| 2,000 mbar | 2 bar |
| 5,000 mbar | 5 bar |
| 10,000 mbar | 10 bar |
Reverse and related
About millibars and bar
Millibar (mbar)
1 mbar = 0.001 barDefinition. Exactly 100 pascals (one hectopascal), one thousandth of a bar — the weather-pressure unit
History and origin
The millibar is one thousandth of a bar, defined as exactly 100 pascals. It became the standard unit in meteorology, where it equals the hectopascal now often used in its place.
Current use
Millibars, or the identical hectopascals, report barometric pressure in weather forecasts and aviation.
Source: NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi)
Bar (bar)
1 bar = 1,000 mbarDefinition. Exactly 100 000 pascals (100 kPa), close to one atmosphere
History and origin
The bar was introduced in the early twentieth century by the meteorologist Vilhelm Bjerknes, defined as exactly 100 000 pascals, close to average sea-level air pressure. Its name comes from the Greek for weight.
Current use
The bar is common outside the United States for tyre pressure, diving and weather, where the closely related millibar is also used.
Source: NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi)
Where people use this
Millibars: weather and barometric pressure, aviation. Bar: tyre pressure outside the US, diving, weather. 1013 mbar is about 1 atmosphere.
Every value is carried to full double precision; the display is rounded.
Both units are defined in NIST SP 811, App. B; ISO 80000-4. Exact SI values are definitional (bar = 10⁵ Pa, atm = 101 325 Pa) or derived from the pound (NIST HB 44) and standard gravity 9.80665 m/s² (psi).
Questions people ask
How many bar is 1000 mbar?
1000 mbar is exactly 1 bar.
How many millibars in a bar?
One bar is exactly 1000 millibars.
What is average sea-level pressure?
About 1013 mbar (1.013 bar), which is one standard atmosphere.