Convert inches of mercury to millibars

1 inHg=33.8639mbar

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

You have

Equals

33.86389

Conversion formula

Forward

millibars = inches of mercury × 33.8639

Reverse

inches of mercury = millibars × 0.02953

Example: 10 inHg × 33.8639 = 338.639 mbar.

About both units

From

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 →

Millibar

mbar

The millibar equals 100 pascals or 1/1000 bar. It is the traditional unit for atmospheric pressure in meteorology (now called hectopascal, hPa, but numerically identical). Sea-level pressure averages 1013 mbar.

Real-world: Sea-level average: 1013 mbar. Deep low-pressure storm: below 980 mbar. Hurricane eye: below 920 mbar.

Read full millibar reference →

Inch of Mercury to Millibar conversion table

Common inches of mercury to millibars values for quick reference.

Inch of Mercury (inHg)	Millibar (mbar)
1 inHg	33.8639 mbar
5 inHg	169.319 mbar
10 inHg	338.639 mbar
25 inHg	846.597 mbar
50 inHg	1,693.19 mbar
100 inHg	3,386.39 mbar
200 inHg	6,772.78 mbar
500 inHg	16,931.95 mbar
1,000 inHg	33,863.89 mbar
5,000 inHg	169,319.45 mbar

Tips & common mistakes

Quick tips

1 inHg ≈ 3386 Pa ≈ 33.86 mbar.
29.92 inHg = 1013.25 mbar = 1 atm.
US pilots use inHg; European pilots use hPa (mbar).

Avoid these

Confusing inHg with mmHg — factor of 25.4.
Mixing US and European altimeter units on a single flight plan.
Using inHg on scientific papers — prefer Pa.

Frequently asked questions

How many millibars in a inch of mercury?

One inch of mercury equals 33.8639 millibars.

How do I convert inches of mercury to millibars?

Multiply the inch of mercury value by 33.8639 to get the equivalent in millibars.

What is 100 inches of mercury in millibars?

100 inches of mercury equals 3,386.39 millibars.

Is a inch of mercury bigger than a millibar?

Yes. 1 inch of mercury equals 33.8639 millibars, so one inch of mercury is larger.

How to convert inches of mercury to millibars without a calculator?

Multiply by 33.86 for a quick estimate; use a calculator for precise results.

Related pressure conversions

📊 See full comparison matrix →

Conversions in other categories

WeightKilogram → Pound LengthKilometer → Mile TemperatureCelsius → Fahrenheit VolumeLiter → US Gallon AreaSquare Meter → Square Foot SpeedKilometer per Hour → Mile per Hour EnergyKilojoule → Kilocalorie PowerKilowatt → Mechanical Horsepower