Convert atmosphere (standard)s to millibars
1 atm = 1013.25 mbar — exactly. Both units are defined against the SI, so this factor is a fraction, not an approximation.
More converter tools
Readable results
Ranges, ± tolerances, feet/inches and clock durations work in the value field.
Unit picker
Export this result
Show this value in all 27 pressure & stress units
- Gigapascals GPa 0.000 101 325
- Megapascals MPa 0.101 325
- Kilopascals kPa 101.325
- Hectopascals hPa 1013.25
- Pascals Pa 101 325
- Millipascals mPa 101 325 000
- Micropascals µPa 101 325 000 000
- Bars bar 1.013 25
- Millibars mbar 1013.25
- Atmosphere (standard)s atm 1
- Atmosphere (technical)s at 1.033 227 452 8
- Torrs Torr 760
- Millitorrs mTorr 760 000
- Millimeter of mercurys mmHg 759.999 891 726
- Centimeter of mercurys cmHg 75.999 989 172 6
- Inch of mercurys inHg 29.921 255 579 7
- Millimeter of waters mmH₂O 10 332.274 528
- Centimeter of waters cmH₂O 1033.227 452 8
- Inch of waters inH₂O 406.782 461 732
- Foot of waters ftH₂O 33.898 538 477 7
- Pound per square inchs psi 14.695 948 775 5
- Kilopound per square inchs ksi 0.014 695 948 775 5
- Pound per square foots psf 2116.216 623 67
- Kilogram-force per square centimeters kgf/cm² 1.033 227 452 8
- Kilogram-force per square meters kgf/m² 10 332.274 528
- Newton per square millimeters N/mm² 0.101 325
- Dyne per square centimeters dyn/cm² 1 013 250
Every row is Atmosphere (standard) (atm) converted through the pascal, in exact rational arithmetic.
How to convert atmosphere (standard)s to millibars
Multiply the number of atmosphere (standard)s by 1013.25 to get millibars.
The exact factor is 1013.25 — as a fraction, 4053/4.
Atmosphere (standard): Exactly 101 325 Pa by definition.
Millibar: Identical to the hectopascal used on modern weather charts.
Atmosphere (standard) to Millibar conversion table
| Atmosphere (standard)s (atm) | Millibars (mbar) |
|---|---|
| 1 atm | 1013.25 |
| 2 atm | 2026.5 |
| 3 atm | 3039.75 |
| 5 atm | 5066.25 |
| 10 atm | 10 132.5 |
| 20 atm | 20 265 |
| 25 atm | 25 331.25 |
| 50 atm | 50 662.5 |
| 100 atm | 101 325 |
| 250 atm | 253 312.5 |
| 500 atm | 506 625 |
| 1000 atm | 1 013 250 |
Millibar to Atmosphere (standard) conversion table
| Millibars (mbar) | Atmosphere (standard)s (atm) |
|---|---|
| 1 mbar | 0.000 986 923 27 |
| 2 mbar | 0.001 973 846 5 |
| 3 mbar | 0.002 960 769 8 |
| 5 mbar | 0.004 934 616 3 |
| 10 mbar | 0.009 869 232 7 |
| 20 mbar | 0.019 738 465 |
| 25 mbar | 0.024 673 082 |
| 50 mbar | 0.049 346 163 |
| 100 mbar | 0.098 692 327 |
| 250 mbar | 0.246 730 82 |
| 500 mbar | 0.493 461 63 |
| 1000 mbar | 0.986 923 27 |
Frequently asked
How many millibars are in a atmosphere (standard)?
One atmosphere (standard) equals 1013.25 millibars (atm → mbar). That figure is exact, not rounded.
How do you convert atmosphere (standard)s to millibars?
Multiply the number of atmosphere (standard)s by 1013.25 to get millibars.
What is 1 mbar in atmosphere (standard)s?
One millibar is 0.0009869232667 atmosphere (standard)s.
What is 10 atm in mbar?
10 atm = 10 132.5 mbar.
What exactly is a atmosphere (standard)?
Exactly 101 325 Pa by definition.
What exactly is a millibar?
Identical to the hectopascal used on modern weather charts.