standard atmosphere to millibar
Convert standard atmosphere (atm) to millibar (mbar). Use an editable pressure converter, conversion formula, and reference table.
1 atm = 1,013.25 mbar
Conversion formula
One standard atmosphere equals 1,013.25 millibar. Multiply your value in standard atmosphere by this factor to get millibar. For the reverse conversion, divide by the same factor.
Worked example
To convert 5 standard atmosphere:5 × 1,013.25 = 5,066.25 mbar
Conversion table
| standard atmosphere (atm) | millibar (mbar) |
|---|---|
| 0.01 | 10.1325 |
| 0.1 | 101.325 |
| 1 | 1,013.25 |
| 2 | 2,026.5 |
| 5 | 5,066.25 |
| 10 | 10,132.5 |
| 25 | 25,331.25 |
| 50 | 50,662.5 |
| 100 | 101,325 |
| 1000 | 1,013,250 |
About these measurements
Pressure is force per unit of area.
The base reference used here is the pascal. One standard atmosphere is 101,325 base units; one millibar is 100 base units.
Important distinctions
Gauge and absolute pressures must not be mixed. This converts units without changing the reference pressure.
Precision
The converter uses stored conversion factors and floating-point arithmetic. Results display up to ten significant digits, switching to scientific notation for very small or large values. Keep the precision of your original measurement when reporting results.
Common questions
How do I convert atm to mbar?
Multiply the quantity in atm by 1,013.25. You can also type the value into the converter above.
Can I reverse the conversion?
Yes. Use the swap button or open the millibar to standard atmosphere converter.
Reference
NIST Guide to the SI — conversion factors and prefix conventions. SI prefixes scale units by powers of ten; the dimension-specific notes above describe the assumptions used on this page.
