Table Of Contents
Millibar to atmospheres Conversion
1 millibar (mbar) is equal to 0.0009869232667 atmospheres (atm).
1 mbar = 0.0009869232667 atm
or
1 atm = 1013.25 mbar
Formula
To convert a pressure from millibar (mbar) to atmospheres (atm), divide the pressure in millibar by 1013.25
p(atm) = p(mbar) / 1013.25
Examples:
Convert 1 millibar to atmospheres:
p(atm) = 1mbar / 1013.25 = 0.0009869232667 atm
Conversion table
| Millibar (mbar) | Atmospheres (atm) |
|---|---|
| 1 mbar | 9.86923e-4 atm |
| 2 mbar | 0.001973847 atm |
| 3 mbar | 0.00296077 atm |
| 5 mbar | 0.004934616 atm |
| 10 mbar | 0.009869233 atm |
| 20 mbar | 0.019738465 atm |
| 25 mbar | 0.024673082 atm |
| 50 mbar | 0.049346163 atm |
| 100 mbar | 0.098692327 atm |
| 250 mbar | 0.246730817 atm |
| 500 mbar | 0.493461633 atm |
| 1000 mbar | 0.986923267 atm |
| Atmospheres (atm) | Millibar (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 |
| 25 atm | 25331.25 mbar |
| 50 atm | 50662.5 mbar |
| 100 atm | 101325 mbar |
| 250 atm | 253312.5 mbar |
| 500 atm | 506625 mbar |
| 1000 atm | 1013250 mbar |
Frequently asked questions
How do I convert millibar to atmospheres?
Divide the value in millibar by 1013.25 to get the result in atmospheres. For example, 5 mbar ÷ 1013.25 = 0.004934616 atm.
How many atmospheres are in 1 millibar?
1 millibar (mbar) is equal to 9.86923e-4 atmospheres (atm).
How do I convert atmospheres back to millibar?
Use the inverse operation: multiply the value in atmospheres by 1013.25 to get the result in millibar.
How accurate is the millibar to atmospheres conversion?
The converter multiplies by the conversion factor 1013.25 and rounds the result to 9 decimal places by default. You can increase or reduce the precision with the digits option on this page.
Sources
Conversion factors are based on internationally recognised standards:
- BIPM — The International System of Units (SI Brochure, 9th edition)
- ISO 80000-4:2019 — Quantities and units — Part 4: Mechanics
- NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically (NIST SP 811, 2008 edition)
- Resolution 4 of the 10th CGPM (1954): Definition of the standard atmosphere
