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Vacuum

inHgtombar

Convert inches of mercury (vacuum) (inHg) to millibars (vacuum) (mbar).

Factor1 inHg = 33.86389 mbar

Converter

inHg

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

Result
1015.92mbar

Rendered to 6 significant figures.

Formula

Formula
mbar = inHg × 33.86389

Multiply any value in inches of mercury (vacuum) by 33.86389 to obtain the value in millibars (vacuum).

Worked example

Convert 30 inHg to mbar.

  1. 01Start with 30 inHg.
  2. 02Multiply by the conversion factor: 30 × 33.86389 = 1015.92 mbar.
Result30 inHg = 1015.92 mbar

Conversion table

inHgmbar
133.864
267.728
5169.32
10338.64
20677.28
501693.2
1003386.4
2006772.8
50016932
100033864

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from inHg to mbar?
1 inHg equals 33.86389 mbar. To convert, multiply the value in inches of mercury (vacuum) by 33.86389.
How do I convert 1 inHg to mbar?
1 inHg = 33.8639 mbar. For any value, multiply by 33.86389.
How do I convert mbar back to inHg?
Divide by the same factor — or equivalently, multiply by 0.02952998. So 1 mbar = 0.02953 inHg.
When would I need to convert inch of mercury (vacuum) to millibar (vacuum)?
Vacuum-pressure conversions between inHg 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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