Barometric Pressure Converter
Convert barometric pressure between inHg, hPa, mbar, atm, and psi.
Includes weather forecast interpretation.
Pressure Conversion
Barometric pressure is the weight of the atmosphere above you. It is one of the best indicators of upcoming weather changes.
Standard atmospheric pressure at sea level:
- 29.92 inHg (inches of mercury)
- 1013.25 hPa (hectopascals)
- 1013.25 mbar (millibars)
- 1.0 atm (atmospheres)
- 14.696 psi (pounds per square inch)
Weather interpretation:
- Above 30.20 inHg (1023 hPa): High pressure — fair, dry weather
- 29.80–30.20 inHg (1009–1023 hPa): Normal — steady conditions
- Below 29.80 inHg (1009 hPa): Low pressure — clouds, rain likely
- Rapidly falling: Storm approaching
- Rapidly rising: Clearing skies
Pressure decreases with altitude at roughly 1 inHg per 1,000 ft (34 hPa per 300 m).