Choose a Measurement
Select a measurement and convert between different units
Single conversion
To convert from Inch of mercury (inHg) to pascal (Pa), use the following formula:
With is the ratio between the base units kilopascal (kPa) and kilopound per square inch (ksi).
Let's convert 5 Inch of mercury (inHg) to pascal (Pa).
Using the formula:
Therefore, 5 Inch of mercury (inHg) is equal to pascal (Pa).
Here are some quick reference conversions from Inch of mercury (inHg) to pascal (Pa):
| Inches of mercury | pascals |
|---|---|
| 0.000001 inHg | Pa |
| 0.001 inHg | Pa |
| 0.1 inHg | Pa |
| 1 inHg | Pa |
| 2 inHg | Pa |
| 3 inHg | Pa |
| 4 inHg | Pa |
| 5 inHg | Pa |
| 6 inHg | Pa |
| 7 inHg | Pa |
| 8 inHg | Pa |
| 9 inHg | Pa |
| 10 inHg | Pa |
| 20 inHg | Pa |
| 30 inHg | Pa |
| 40 inHg | Pa |
| 50 inHg | Pa |
| 100 inHg | Pa |
| 1000 inHg | Pa |
| 10000 inHg | Pa |
For all Pressure converters, choose units using the From/To dropdowns above.
An inch of mercury, often abbreviated as inHg, is a unit of pressure.
It is not part of the standard metric (SI) system but is widely used in the United States and in specific fields like meteorology and aviation.
The unit is defined by its name: it is the amount of pressure exerted by a column of liquid mercury exactly one inch tall at a standard temperature.
You will most commonly encounter inches of mercury in a few key areas:
Weather Reporting: In the U.S., inHg is the standard unit for reporting barometric pressure (also known as atmospheric pressure).
A "high" pressure system indicating clear weather might be around 30.50 inHg, while a "low" pressure system associated with storms could be 28.50 inHg.
Aviation: This measurement is critical for pilot safety.
Pilots use the local barometric pressure (in inHg) to calibrate their altimeters—instruments that measure altitude—to ensure they are flying at the correct height.
Vacuum Systems: The unit is also widely used in science and industry to measure vacuum pressure.
This is common in systems like air conditioning, refrigeration, and for monitoring the manifold pressure in piston engines.
Because inHg is not a global standard, it's often necessary to convert it to other pressure units for calculations or international use.
Here are the most common conversions for 1 inHg:
A pascal (Pa) is the standard unit of pressure in the International System of Units (SI). It is a derived unit, meaning other base units define it.
The primary pascal definition is one newton of force applied over an area of one square meter (1 Pa = 1 N/m2).
Because a single pascal represents a very small amount of pressure, it is most often seen in multiples.
The most common multiples are the kilopascal (kPa), equal to 1,000 pascals, and the megapascal (MPa), equal to 1,000,000 pascals.
These units are widely used in fields from weather forecasting to material science.
The pascal (Pa) unit is named in honor of Blaise Pascal, a key 17th-century French mathematician, physicist, and inventor.
His groundbreaking work on how fluids behave under pressure (known as hydrodynamics and hydrostatics) and his formulation of Pascal's Law were essential to our modern understanding of pressure.
To understand just how small a single pascal is, here are two real-world examples:
This shows why, for most everyday measurements (like tire pressure or weather), the larger kilopascal (kPa) is much more practical.