🌡️ mmHg to inHg — mmHg to Inch Hg Converter

Convert pressure units — pascal, PSI, bar, atmosphere, torr, mmHg and more.

1 unit =
From
To
Formula 1 mmHg = 0.03937 inHg
UnitNameValue
0.001 mmHg3.93699e-05 inHg
0.01 mmHg0.000393699 inHg
0.1 mmHg0.00393699 inHg
1 mmHg0.0393699 inHg
5 mmHg0.19685 inHg
10 mmHg0.393699 inHg
50 mmHg1.9685 inHg
100 mmHg3.93699 inHg
1000 mmHg39.3699 inHg

Quick Answer

Formula: Inch Hg = mmHg × 0.03937

Multiply any mmhg value by 0.03937 to get inch hg.

Reverse: mmHg = Inch Hg × 25.4

Worked Examples

1 mmHg
1 mmHg × 0.03937 = 0.03937 inHg
Single unit reference.
10 mmHg
10 mmHg × 0.03937 = 0.3937 inHg
10 units — low pressure range.
100 mmHg
100 mmHg × 0.03937 = 3.937 inHg
100 units — moderate pressure.
1000 mmHg
1000 mmHg × 0.03937 = 39.37 inHg
1,000 units — high pressure reference.

mmHg to Inch Hg Conversion Table

Common mmhg values — factor: 1 mmHg = 0.03937 inHg

mmHg (mmHg)Inch Hg (inHg)Context
1 mmHg0.03937 inHgVery low / ophthalmic
5 mmHg0.1968 inHgLow IOP
10 mmHg0.3937 inHgDiastolic minimum
20 mmHg0.7874 inHgLow BP diastolic
40 mmHg1.575 inHgLow BP range
60 mmHg2.362 inHgHypotensive
80 mmHg3.15 inHgNormal diastolic
100 mmHg3.937 inHgElevated diastolic
120 mmHg4.724 inHgNormal systolic
200 mmHg7.874 inHgHigh BP
300 mmHg11.81 inHgHypertensive crisis
760 mmHg29.92 inHg1 atm
1,000 mmHg39.37 inHgAbove atm
2,000 mmHg78.74 inHg~2.6 atm
1e+04 mmHg393.7 inHg~13 atm

Mental Math Tricks

Exact factor

1 mmHg = 0.03937 inHg. Memorize for instant estimates.

Rounded shortcut

Use 0.0394 as a quick mental multiplier.

Reverse check

Multiply result by 25.4 to recover the original mmHg value.

Who Uses This Conversion?

Cardiologist

Measures and interprets blood pressure in mmHg — the global clinical standard.

Ophthalmologist

Measures intraocular pressure in mmHg to screen for and manage glaucoma.

Anesthesiologist

Monitors arterial blood pressure and ventilator settings in mmHg.

Vacuum Engineer

Specifies rough vacuum ranges in torr/mmHg for laboratory systems.

Pulmonologist

Measures pulmonary artery pressure and oxygen partial pressure in mmHg.

Physiologist

Quantifies gas partial pressures (O₂, CO₂) in blood and tissues in mmHg.

Frequently Asked Questions

About mmHg and Inch Hg

mmHg (mmHg)

Millimeters of mercury (mmHg) is the traditional medical pressure unit, defined as the pressure exerted by a 1 mm column of mercury at 0°C under standard gravity. It equals 133.322 Pa and is numerically identical to the torr.

Blood pressure is universally measured in mmHg worldwide: normal blood pressure is about 120/80 mmHg. Intraocular pressure (glaucoma screening) is measured in mmHg. Gas partial pressures in physiology are quoted in mmHg.

Interesting fact: The sphygmomanometer (blood pressure cuff) still uses mmHg more than 130 years after its invention, making mmHg one of the most clinically important pressure units despite not being an SI unit.

Inch Hg (inHg)

Inches of mercury (inHg) is the pressure unit used in US aviation and weather reporting, defined as the pressure exerted by a 1-inch column of mercury (3,386.39 Pa). It has been standard in US aviation since the early 20th century.

US aviation altimeters are set in inHg (standard: 29.92 inHg). US weather broadcasts report barometric pressure in inHg. HVAC engineers in the US use inHg for duct static pressure measurements.

Interesting fact: Pilots set their altimeter to the local QNH (pressure at sea level) in inHg to ensure their altitude reading is accurate — a difference of 0.1 inHg causes an altimeter error of about 100 feet.

About mmHg to Inch Hg Conversion

Converting mmhg to inch hg is a common task in engineering, medicine, meteorology, and science. Different industries and countries use different pressure units — PSI in the US, bar in Europe, mmHg in medicine, and pascals in physics — making accurate conversion essential for cross-disciplinary work.

Quick reference: 5 mmHg = 0.1968 inHg and 10 mmHg = 0.3937 inHg. For the reverse: 1 inHg = 25.4 mmHg. The exact factor is 1 mmHg = 0.03937 inHg.

All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.