millibar to standard atmosphere
Convert millibar (mbar) to standard atmosphere (atm). Use an editable pressure converter, conversion formula, and reference table.
1 mbar = 0.0009869232667 atm
Conversion formula
One millibar equals 0.0009869232667 standard atmosphere. Multiply your value in millibar by this factor to get standard atmosphere. For the reverse conversion, divide by the same factor.
Worked example
To convert 5 millibar:5 × 0.0009869232667 = 0.004934616334 atm
Conversion table
| millibar (mbar) | standard atmosphere (atm) |
|---|---|
| 0.01 | 0.000009869232667 |
| 0.1 | 0.00009869232667 |
| 1 | 0.0009869232667 |
| 2 | 0.001973846533 |
| 5 | 0.004934616334 |
| 10 | 0.009869232667 |
| 25 | 0.02467308167 |
| 50 | 0.04934616334 |
| 100 | 0.09869232667 |
| 1000 | 0.9869232667 |
About these measurements
Pressure is force per unit of area.
The base reference used here is the pascal. One millibar is 100 base units; one standard atmosphere is 101,325 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 mbar to atm?
Multiply the quantity in mbar by 0.0009869232667. You can also type the value into the converter above.
Can I reverse the conversion?
Yes. Use the swap button or open the standard atmosphere to millibar 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.
