Vacuum
mTorrtoinHg
Convert millitorr (mTorr) to inches of mercury (vacuum) (inHg).
Factor1 mTorr = 3.937007e-5 inHg
Converter
mTorr
Accepts numbers or expressions, e.g. 150 + 14.7
Result
inHg
Rendered to 6 significant figures.
Formula
Formula
inHg = mTorr × 3.937007e-5
Multiply any value in millitorr by 3.937007e-5 to obtain the value in inches of mercury (vacuum).
Worked example
Convert 25400 mTorr to inHg.
- 01Start with 25400 mTorr.
- 02Multiply by the conversion factor: 25400 × 3.937007e-5 = 1 inHg.
Result25400 mTorr = 1 inHg
Conversion table
| mTorr | inHg |
|---|---|
| 1 | 3.937e-5 |
| 2 | 7.874e-5 |
| 5 | 0.00019685 |
| 10 | 0.0003937 |
| 20 | 0.0007874 |
| 50 | 0.0019685 |
| 100 | 0.003937 |
| 200 | 0.007874 |
| 500 | 0.019685 |
| 1000 | 0.03937 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from mTorr to inHg?
1 mTorr equals 3.937007e-5 inHg. To convert, multiply the value in millitorr by 3.937007e-5.
How do I convert 1 mTorr to inHg?
1 mTorr = 3.93701e-5 inHg. For any value, multiply by 3.937007e-5.
How do I convert inHg back to mTorr?
Divide by the same factor — or equivalently, multiply by 25400.01. So 1 inHg = 25400 mTorr.
When would I need to convert millitorr to inch of mercury (vacuum)?
Vacuum-pressure conversions between mTorr 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).