UnitConvConvert
Pressure

Convert atmospheres to inches of mercury

1 atm=29.9213inHg

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

29.92125

Conversion formula

Forward
inches of mercury = atmospheres × 29.9213
Reverse
atmospheres = inches of mercury × 0.03342

Example: 10 atm × 29.9213 = 299.213 inHg.

About both units

From

Atmosphere

atm

The standard atmosphere equals 101,325 pascals exactly — defined by CGPM in 1954. Represents average sea-level atmospheric pressure. Used in chemistry, aviation and engineering as a reference pressure.

Real-world: Sea-level pressure: 1 atm. Mount Everest summit: ~0.33 atm. Submarine at 100 m: ~11 atm.
Read full atmosphere 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 →

Atmosphere to Inch of Mercury conversion table

Common atmospheres to inches of mercury values for quick reference.

Atmosphere (atm)Inch of Mercury (inHg)
1 atm29.9213 inHg
5 atm149.606 inHg
10 atm299.213 inHg
25 atm748.031 inHg
50 atm1,496.06 inHg
100 atm2,992.13 inHg
200 atm5,984.25 inHg
500 atm14,960.63 inHg
1,000 atm29,921.25 inHg
5,000 atm149,606.26 inHg

Tips & common mistakes

Quick tips

  • 1 atm = 101,325 Pa = 1.01325 bar = 14.696 psi.
  • Note: atm ≠ bar. Close but not identical.
  • Modern SI prefers pascals; atm is a legacy reference.

Avoid these

  • Using 1 atm = 1 bar exactly — off by 1.3%.
  • Confusing standard atm with technical atmosphere (98,066.5 Pa) or atmosphere-absolute in diving.
  • Applying 1 atm outside sea level without correction.

Frequently asked questions

How many inches of mercury in a atmosphere?
One atmosphere equals 29.9213 inches of mercury.
How do I convert atmospheres to inches of mercury?
Multiply the atmosphere value by 29.9213 to get the equivalent in inches of mercury.
What is 100 atmospheres in inches of mercury?
100 atmospheres equals 2,992.13 inches of mercury.
Is a atmosphere bigger than a inch of mercury?
Yes. 1 atmosphere equals 29.9213 inches of mercury, so one atmosphere is larger.
How to convert atmospheres to inches of mercury without a calculator?
Multiply by 29.92 for a quick estimate; use a calculator for precise results.

Related pressure conversions

📊 See full comparison matrix →

More from Atmosphere

atm → Pa
1 = 101,325 Pa
atm → kPa
1 = 101.325 kPa
atm → MPa
1 = 0.1013 MPa
atm → bar
1 = 1.01325 bar
atm → mbar
1 = 1,013.25 mbar
atm → psi
1 = 14.6959 psi
atm → mmHg
1 = 760 mmHg
atm → Torr
1 = 760 Torr

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
mmHg → inHg
1 = 0.03937 inHg
Torr → inHg
1 = 0.03937 inHg

Conversions in other categories

WeightKilogram → PoundLengthKilometer → MileTemperatureCelsius → FahrenheitVolumeLiter → US GallonAreaSquare Meter → Square FootSpeedKilometer per Hour → Mile per HourEnergyKilojoule → KilocaloriePowerKilowatt → Mechanical Horsepower