How many pascals are in one inch of mercury?

One inch of mercury (inHg) equals 3,386.389 pascals (Pa). This is based on 0 °C (32 °F) mercury density per the NIST definition.

How do I convert inHg to pascals manually?

Multiply the inHg value by 3,386.389. For example, 29.92 inHg × 3,386.389 = 101,320.76 Pa, very close to standard atmosphere (101,325 Pa).

What is standard atmospheric pressure in inHg?

Standard atmospheric pressure is 29.9213 inHg, which equals exactly 101,325 Pa (1 atm). Aviation uses 29.92 inHg as the standard altimeter setting.

What is the difference between inHg and Pa?

The pascal (Pa) is the SI unit of pressure equal to one newton per square meter. Inches of mercury (inHg) is a traditional unit based on the height of a mercury column. InHg is still common in US weather reports and aviation; Pa is used in science and most international contexts.

Why is inHg used for weather and aviation?

InHg became standard in the US because early barometers physically measured the height of a mercury column. Aviation adopted inHg for altimeter settings in the US and Canada, while most of the rest of the world uses hectopascals (hPa).

What is a typical barometric pressure range in inHg?

Normal sea-level barometric pressure ranges roughly from 27.00 inHg (very strong storm) to 31.00 inHg (exceptionally high pressure). The standard value is 29.92 inHg (101,325 Pa).

inHg to Pascals Converter

Enter a pressure in conventional inches of mercury (inHg) and get the pascal (Pa) equivalent instantly — includes reverse conversion and a reference table.

Converter

Pressure in inches of mercury (inHg)

Result in pascals (Pa)

Reverse: pascals to inHg

Pressure in Pa

Result in inHg

Reference Table

Inches Hg (inHg) Pascals (Pa)

27.00 inHg (strong storm) 91,432 Pa

28.00 inHg (low pressure) 94,819 Pa

29.00 inHg (below normal) 98,205 Pa

29.53 inHg (100 kPa) 100,000 Pa

29.92 inHg (std. aviation) 101,321 Pa

29.9213 inHg (1 atm) 101,325 Pa

30.00 inHg (normal high) 101,592 Pa

30.50 inHg (high pressure) 103,285 Pa

31.00 inHg (very high) 104,978 Pa

Summary

This converter turns any conventional inches-of-mercury (inHg) value into pascals (Pa) using the NIST factor of 1 inHg ≈ 3,386.389 Pa. All math runs in your browser with no server round-trips. A reverse field lets you go from Pa back to inHg, and a reference table covers common barometric pressures from stormy to fair-weather conditions and standard aviation altimeter settings.

How it works

Enter the pressure value in inches of mercury (inHg) in the top input field.
The converter multiplies your value by 3,386.389 to get pascals.
The result updates instantly as you type.
Use the reverse field to convert pascals back to inHg.
Click "Copy" next to any result to copy it to the clipboard.
Check the reference table for common inHg barometric pressure values.

Use cases

Convert weather station barometric pressure readings from inHg to Pa for calculations.
Translate aviation altimeter settings (e.g. 29.92 inHg) to pascals for engineering specs.
Cross-check meteorological data that mixes inHg and Pa pressure units.
Convert US-format barometric pressure reports (inHg) to the SI unit (Pa).
Verify HVAC and industrial pressure sensor ratings expressed in inHg.
Convert historical weather records from inHg to pascals for scientific analysis.

Frequently Asked Questions

Last updated: 2026-06-19 · Reviewed by Nham Vu