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Vacuum

mmHgtoinHg

Convert millimetres of mercury (vacuum) (mmHg) to inches of mercury (vacuum) (inHg).

Factor1 mmHg = 0.03937007 inHg

Converter

mmHg

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

Result
29.9213inHg

Rendered to 6 significant figures.

Formula

Formula
inHg = mmHg × 0.03937007

Multiply any value in millimetres of mercury (vacuum) by 0.03937007 to obtain the value in inches of mercury (vacuum).

Worked example

Convert 760 mmHg to inHg.

  1. 01Start with 760 mmHg.
  2. 02Multiply by the conversion factor: 760 × 0.03937007 = 29.9213 inHg.
Result760 mmHg = 29.9213 inHg

Conversion table

mmHginHg
10.03937
20.07874
50.19685
100.3937
200.7874
501.9685
1003.937
2007.874
50019.685
100039.37

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from mmHg to inHg?
1 mmHg equals 0.03937007 inHg. To convert, multiply the value in millimetres of mercury (vacuum) by 0.03937007.
How do I convert 1 mmHg to inHg?
1 mmHg = 0.0393701 inHg. For any value, multiply by 0.03937007.
How do I convert inHg back to mmHg?
Divide by the same factor — or equivalently, multiply by 25.4. So 1 inHg = 25.4 mmHg.
When would I need to convert millimetre of mercury (vacuum) to inch of mercury (vacuum)?
Vacuum-pressure conversions between mmHg and inHg 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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