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Convert millibar to standard atmosphere

Here you can quickly calculate how many standard atmosphere fit in one millibar.
  • 1 mbar = 0.000987 atm
  • 1 atm = 1013.25 mbar

Millibar to standard atmosphere conversion table

millibar standard atmosphere
1 0.000987
2 0.001974
5 0.004935
10 0.009869
20 0.019738
50 0.049346
100 0.098692

Formula to convert millibar to standard atmosphere

To convert millibar to standard atmosphere, multiply by 0.000987.

1 mbar = 0.000987 atm
Example: 1 millibar = 0.000987 standard atmosphere

Common mistakes in pressure conversion

  • One atmosphere is not exactly one bar: 1 atm = 1.01325 bar = 101.325 kPa. There is also the technical atmosphere (1 kgf/cm²) at about 0.981 bar. The ~1% differences rarely matter day to day, but engineering and diving calculations need the right unit.
  • Blood pressure uses mmHg (120/80) and weather reports use hPa (around 1,013), different units that must not be mixed: 760 mmHg = 1,013.25 hPa. One mmHg is about 1.33 hPa.
  • Hectopascals and millibars are exactly the same size: 1 hPa = 1 mbar. A chart showing 1,013 mbar and one showing 1,013 hPa agree perfectly, no conversion needed. Meteorology simply renamed the unit.

Quick millibar to/from standard atmosphere conversion quiz

Score: 0

2 standard atmosphere equals 2.03e+3 millibar.

Correct answer: 2 standard atmosphere = 2.03e+3 millibar.

2 millibar equals 0.00197 standard atmosphere.

Correct answer: 2 millibar = 0.00197 standard atmosphere.

50 standard atmosphere equals 5.07e+4 millibar.

Correct answer: 50 standard atmosphere = 5.07e+4 millibar.

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