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Pressure

Convert torr to inches of mercury

1 Torr=0.03937inHg

Use the converter below to change any torr value into inches of mercury instantly — with formula, conversion table, and real-world examples.

0.03937

Conversion formula

Forward
inches of mercury = torr × 0.03937
Reverse
torr = inches of mercury × 25.4

Example: 10 Torr × 0.03937 = 0.3937 inHg.

About both units

From

Torr

Torr

The torr equals 1/760 atm — approximately 133.32 Pa. Essentially equivalent to mmHg but defined slightly differently. Used in vacuum-system engineering and older physics.

Real-world: Low-vacuum: 760 to 25 torr. High-vacuum: 10⁻³ to 10⁻⁹ torr. Semiconductor fabrication: often below 10⁻⁶ torr.
Read full torr reference →
To

Inch of Mercury

inHg

The inch of mercury equals about 3386 Pa. Used in US barometers, US aviation altimeter settings and some engineering. Standard sea-level pressure: 29.92 inHg.

Real-world: Sea-level standard: 29.92 inHg. Mountain pass at 3000 m: ~21 inHg. US aviation QNH given in inHg.
Read full inch of mercury reference →

Torr to Inch of Mercury conversion table

Common torr to inches of mercury values for quick reference.

Torr (Torr)Inch of Mercury (inHg)
1 Torr0.03937 inHg
5 Torr0.1969 inHg
10 Torr0.3937 inHg
25 Torr0.9843 inHg
50 Torr1.9685 inHg
100 Torr3.93701 inHg
200 Torr7.87401 inHg
500 Torr19.685 inHg
1,000 Torr39.3701 inHg
5,000 Torr196.85 inHg

Tips & common mistakes

Quick tips

  • 1 Torr ≈ 1 mmHg (differ by ~1 ppm — negligible in practice).
  • 1 atm = 760 Torr exactly.
  • Named after Evangelista Torricelli, inventor of the barometer.

Avoid these

  • Assuming torr and mmHg are truly identical — they differ by ~10⁻⁷; only matters in metrology.
  • Using Torr in everyday context — obscure outside vacuum engineering.
  • Mixing Torr and mTorr without specification.

Frequently asked questions

How many inches of mercury in a torr?
One torr equals 0.03937 inches of mercury.
How do I convert torr to inches of mercury?
Multiply the torr value by 0.03937 to get the equivalent in inches of mercury.
What is 100 torr in inches of mercury?
100 torr equals 3.93701 inches of mercury.
Is a torr bigger than a inch of mercury?
No. 1 torr equals 0.03937 inches of mercury, so one torr is smaller.
How to convert torr to inches of mercury without a calculator?
Multiply by 0.04 for a quick estimate; use a calculator for precise results.

Related pressure conversions

📊 See full comparison matrix →

More from Torr

Torr → Pa
1 = 133.322 Pa
Torr → kPa
1 = 0.1333 kPa
Torr → MPa
1 = 0.0001333 MPa
Torr → bar
1 = 0.001333 bar
Torr → mbar
1 = 1.33322 mbar
Torr → psi
1 = 0.01934 psi
Torr → atm
1 = 0.001316 atm
Torr → mmHg
1 = 1 mmHg

More to Inch of Mercury

Pa → inHg
1 = 0.0002953 inHg
kPa → inHg
1 = 0.2953 inHg
MPa → inHg
1 = 295.3 inHg
bar → inHg
1 = 29.53 inHg
mbar → inHg
1 = 0.02953 inHg
psi → inHg
1 = 2.03602 inHg
atm → inHg
1 = 29.9213 inHg
mmHg → inHg
1 = 0.03937 inHg

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