Atmospheres (atm) to Millibar (mbar) Conversion
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
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 (atm) | Millibar (mbar) |
|---|---|
| 0.1 atm | 101.325 mbar |
| 1 atm | 1013.25 mbar |
| 2 atm | 2026.5 mbar |
| 3 atm | 3039.75 mbar |
| 5 atm | 5066.25 mbar |
| 10 atm | 10132.5 mbar |
| 20 atm | 20265 mbar |
| 30 atm | 30397.5 mbar |
| 50 atm | 50662.5 mbar |
| 100 atm | 101325 mbar |
| 1000 atm | 1013250 mbar |
Frequently Asked Questions (FAQ)
How many millibar are in 1 atmospheres?
1 atmospheres (atm) is exactly 1,013.25 millibar (mbar).
How do I convert atmospheres to millibar?
Multiply the value in atmospheres by 1,013.25 to get the result in millibar. Or use the converter above — type any number and see the result instantly.