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Vacuum

atmtommHg

Convert standard atmospheres (vacuum) (atm) to millimetres of mercury (vacuum) (mmHg).

Factor1 atm = 759.9999 mmHg

Converter

atm

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

Result
760mmHg

Rendered to 6 significant figures.

Formula

Formula
mmHg = atm × 759.9999

Multiply any value in standard atmospheres (vacuum) by 759.9999 to obtain the value in millimetres of mercury (vacuum).

Worked example

Convert 1 atm to mmHg.

  1. 01Start with 1 atm.
  2. 02Multiply by the conversion factor: 1 × 759.9999 = 760 mmHg.
Result1 atm = 760 mmHg

Conversion table

atmmmHg
1760
21520
53800
107600
2015200
5038000
10076000
2001.5200e+5
5003.8000e+5
10007.6000e+5

Reference values rounded to 5 significant figures for display.

FAQ

What is the conversion factor from atm to mmHg?
1 atm equals 759.9999 mmHg. To convert, multiply the value in standard atmospheres (vacuum) by 759.9999.
How do I convert 1 atm to mmHg?
1 atm = 760 mmHg. For any value, multiply by 759.9999.
How do I convert mmHg back to atm?
Divide by the same factor — or equivalently, multiply by 0.00131579. So 1 mmHg = 0.00131579 atm.
When would I need to convert standard atmosphere (vacuum) to millimetre of mercury (vacuum)?
Vacuum-pressure conversions between atm and mmHg 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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