processconvert
Vacuum

bartombar

Convert bar (vacuum) (bar) to millibars (vacuum) (mbar).

Factor1 bar = 1000 mbar

Converter

bar

Accepts numbers or expressions, e.g. 150 + 14.7

Result
1000mbar

Rendered to 6 significant figures.

Formula

Formula
mbar = bar × 1000

Multiply any value in bar (vacuum) by 1000 to obtain the value in millibars (vacuum).

Worked example

Convert 1 bar to mbar.

  1. 01Start with 1 bar.
  2. 02Multiply by the conversion factor: 1 × 1000 = 1000 mbar.
Result1 bar = 1000 mbar

Conversion table

barmbar
11000
22000
55000
1010000
2020000
5050000
1001.0000e+5
2002.0000e+5
5005.0000e+5
10001.0000e+6

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from bar to mbar?
1 bar equals 1000 mbar. To convert, multiply the value in bar (vacuum) by 1000.
How do I convert 1 bar to mbar?
1 bar = 1000 mbar. For any value, multiply by 1000.
How do I convert mbar back to bar?
Divide by the same factor — or equivalently, multiply by 0.001. So 1 mbar = 0.001 bar.
When would I need to convert bar (vacuum) to millibar (vacuum)?
Vacuum-pressure conversions between bar and mbar are common in vacuum-chamber instrumentation, pump-down endpoint specification, semiconductor and deposition process work, freeze-drying, electron-microscopy column pressure, vacuum metallurgy and HVAC / refrigeration service. Torr, mmHg and inHg dominate manometric vacuum gauges; mbar is standard on European instruments; micron Hg and mTorr cover high-vacuum work; Pa and kPa are the SI references. This category is vacuum / instrumentation intent — dimensionally the same as pressure, but kept separate so process-pressure searches and vacuum searches stay on the right page.
Is the conversion exact?
The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).

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