Barometric Pressure Converter

Type into any field — the others update instantly. Standard sea-level pressure is 1013.25 mb / 29.92 inHg.

Millibars (mb / hPa)

Inches of Mercury (inHg)

Kilopascals (kPa)

Millimeters of Mercury (mmHg / Torr)

Pounds per Square Inch (psi)

Atmospheres (atm)

Pressure Reference Chart

Pressure (mb)	inHg	Context	Category
1084	32.01	Highest recorded sea-level (Siberia, 1968)	Record high
1030	30.42	Strong high-pressure system	High
1013.25	29.92	Standard sea-level pressure	Normal
1000	29.53	Approaching low pressure	Normal
985	29.08	Modest cyclone / winter storm	Low
975	28.79	Nor'easter / strong midlatitude storm	Low
960	28.35	Cat 2 hurricane / bomb cyclone	Very low
945	27.90	Cat 3 hurricane center	Extreme low
920	27.17	Cat 4 hurricane center	Extreme low
882	26.05	Hurricane Wilma (2005) — Atlantic record	Record
870	25.69	Typhoon Tip (1979) — world record	World record
~850	~25.10	Estimated inside violent tornadoes	Tornado core

Why pressure matters for weather

Air flows from high pressure to low pressure. Big pressure differences (steep gradients) produce strong winds. Storm intensity is often measured by central pressure — the deeper the low, the stronger the storm.

Inside violent tornadoes, pressure drops of 100 mb or more have been indirectly measured. This creates the explosive pressure differential responsible for structural damage even at the edge of the vortex.