Millibar (mbar) to Atmospheres (atm) Conversion
Millibar
The millibar (mbar) is a unit of pressure equal to one thousandth of a bar (100 Pa). It is the standard unit for atmospheric pressure in meteorology: standard atmospheric pressure is 1,013.25 mbar, and weather maps plot isobars (lines of equal pressure) in millibars or hectopascals (1 hPa = 1 mbar). The eye of a powerful hurricane can have a central pressure below 900 mbar, while high-pressure systems typically exceed 1,020 mbar.
Atmospheres
The standard atmosphere (atm) is a unit of pressure defined as exactly 101,325 Pa, representing the approximate mean atmospheric pressure at sea level. It remains in use in chemistry for expressing gas pressures in thermodynamic tables and standard conditions (STP: 0 °C and 1 atm). One atmosphere supports a mercury column of exactly 760 mm — the basis of the mercury barometer invented by Torricelli in 1643. In deep-sea diving, pressure is expressed in atmospheres absolute (ATA).
| Millibar (mbar) | Atmospheres (atm) |
|---|---|
| 0.1 mbar | 9.8692326671601E-5 atm |
| 1 mbar | 0.00098692326671601 atm |
| 2 mbar | 0.001973846533432 atm |
| 3 mbar | 0.002960769800148 atm |
| 5 mbar | 0.0049346163335801 atm |
| 10 mbar | 0.0098692326671601 atm |
| 20 mbar | 0.01973846533432 atm |
| 30 mbar | 0.02960769800148 atm |
| 50 mbar | 0.049346163335801 atm |
| 100 mbar | 0.098692326671601 atm |
| 1000 mbar | 0.98692326671601 atm |
Frequently Asked Questions (FAQ)
How many atmospheres are in 1 millibar?
1 millibar (mbar) is exactly 0.000987 atmospheres (atm).
How do I convert millibar to atmospheres?
Multiply the value in millibar by 0.000987 to get the result in atmospheres. Or use the converter above — type any number and see the result instantly.