Is mbar the same as hPa?

Yes! 1 mbar = 1 hPa exactly (just different names, same value) Millibar (mbar) : Traditional meteorology unit (1900s-1980s) Still used: Aviation, maritime, older weather services Pilots/mariners: "Set altimeter to 1015 millibars" Hectopascal (hPa) : SI-compliant name (1980s-present) Modern: Weather services worldwide officially use hPa Scientific: Consistent with SI unit system No conversion needed : 1,013 mbar = 1,013 hPa (identical) Why two names? : Transition to SI units in 1980s. Chose "hectopascal" because 1 hPa = 1 mbar exactly, making transition seamless. Old term persists in aviation/maritime.

How do I convert mbar to PSI?

Formula : PSI = mbar × 0.0145038 Examples : 1,013 mbar = 14.7 PSI (sea level) 1,000 mbar = 14.5 PSI 900 mbar = 13.05 PSI (storm) 800 mbar = 11.6 PSI 500 mbar = 7.25 PSI (FL180) mbar to PSI converter →

What is normal atmospheric pressure in mbar?

Standard sea level : 1,013.25 mbar (exactly, by definition) Typical range : 980-1,050 mbar depending on weather Pressure variations : Fair weather (high) : 1,020-1,040 mbar Normal range : 1,000-1,020 mbar Stormy (low) : 980-1,000 mbar Hurricane : <980 mbar Regional/seasonal : Varies ±30 mbar from standard Altitude : Decreases ~12 mbar per 100m near sea level

What mbar is considered high or low pressure?

High pressure (anticyclone) : Strong high : >1,030 mbar (stable, clear weather) Moderate high : 1,020-1,030 mbar (fair weather) Normal pressure : 1,005-1,020 mbar Low pressure (cyclone) : Moderate low : 990-1,005 mbar (cloudy, possible rain) Strong low : 970-990 mbar (rain, wind) Very low : <970 mbar (storms, gales) Extreme low : <920 mbar (major hurricanes/typhoons) Context matters : 1,000 mbar may be "low" in winter high-pressure region, "high" in tropical area.

Why do pilots still say "millibar" instead of "hectopascal"?

Historical training : Aviation training used mbar for decades International : ICAO (aviation authority) still references millibars Brevity : "Millibar" rolls off tongue easier than "hectopascal" Tradition : Aviation conservative about terminology changes Communication : Older pilots, documents use mbar Modern transition : Official : ICAO now uses hPa in documents Practice : Pilots use both terms interchangeably Altimeter : Settings shown as "1013 hPa" or "1013 mb" No confusion : Since 1 mbar = 1 hPa exactly, using either term causes no errors. Maritime similar : Sailors also prefer "millibar" from tradition.

Millibar (mbar) - Unit Information & Conversion

Symbol:mbar

Plural:millibars

Category:Pressure

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What is a Millibar?

Millibar (mbar) = 100 pascals = 1 hectopascal exactly. Traditional meteorology unit (1900s-1980s). 1 mbar = 1 hPa. Sea level: 1,013.25 mbar. Still used in aviation, maritime, older weather reports.

History of the Millibar

Standard meteorology unit 1900s-1980s. Introduced as convenient unit for atmospheric pressure (sea level ≈ 1,000 mbar). Replaced by hectopascal (hPa) for SI compliance, but 1 mbar = 1 hPa exactly. Pilots, mariners still use "millibar".

Quick Answer

What is a Millibar? Millibar (mbar) = 100 pascals = 1 hectopascal exactly. Traditional weather/aviation unit. Sea level pressure: 1,013.25 mbar. Modern weather reports use hPa (same value). Aviation still says "millibar." Hurricane: <980 mbar. Use our pressure converter for conversions.

Definition

1 mbar = 100 Pa = 1 hPa (exactly) = 0.001 bar = 0.0145 PSI = 0.75 mmHg = 0.000987 atm

Key relationship: 1 mbar = 1 hPa (exact equivalence)

Common Uses

Aviation: Altimeter settings (pilots say "1015 millibars"). Maritime: Marine weather forecasts, ship barometers. Meteorology: Historical weather data (pre-1980s). Diving: Depth pressure calculations (sometimes).

Real-World Examples

Weather System Pressures

Very high pressure: 1,040-1,050 mbar (anticyclone, clear weather)
High pressure system: 1,020-1,035 mbar (fair weather)
Average sea level: 1,013.25 mbar (standard atmosphere)
Low pressure system: 980-1,000 mbar (cloudy, rain)
Storm: 960-980 mbar (strong low pressure)
Hurricane (Category 1): 980-990 mbar
Hurricane (Category 3): 945-965 mbar
Hurricane (Category 5): <920 mbar (extreme)
Strongest hurricane: 882 mbar (Typhoon Tip, 1979)

Altitude Pressure (ISA Standard)

Sea level: 1,013.25 mbar
1,000 ft (305m): 977 mbar
5,000 ft (1,524m): 843 mbar
10,000 ft (3,048m): 697 mbar (cabin pressure)
18,000 ft (5,486m): 500 mbar (FL180)
Mount Everest (29,029 ft): ~313 mbar

Aviation Flight Levels

FL000 (sea level): 1,013 mbar
FL100 (10,000 ft): 697 mbar
FL180 (18,000 ft): 500 mbar
FL300 (30,000 ft): 301 mbar (cruise altitude)
FL390 (39,000 ft): 188 mbar (high cruise)

Geographic Variations

Dead Sea (-430m): ~1,063 mbar (lowest point on Earth)
Amsterdam (sea level): ~1,013 mbar
Denver (1,609m): ~835 mbar
Mexico City (2,240m): ~760 mbar
La Paz, Bolivia (3,640m): ~640 mbar

Pressure Tendencies (Weather Forecasting)

Rising rapidly: +5 to +10 mbar/3hr (improving weather)
Rising slowly: +1 to +3 mbar/3hr (gradual improvement)
Steady: -1 to +1 mbar/3hr (stable conditions)
Falling slowly: -1 to -3 mbar/3hr (deteriorating)
Falling rapidly: -5 to -10 mbar/3hr (storm approaching)

Millibar Conversion Formulas

To Pascal:

1 mbar = 100 Pa

Example: 5 millibars = 500 pascals

To Kilopascal:

1 mbar = 0.1 kPa

Example: 5 millibars = 0.5 kilopascals

To Megapascal:

1 mbar = 0.0001 MPa

Example: 5 millibars = 0.0005 megapascals

To Hectopascal:

1 mbar = 1 hPa

Example: 5 millibars = 5 hectopascals

To Bar:

1 mbar = 0.001 bar

Example: 5 millibars = 0.005 bars

To Atmosphere:

1 mbar = 0.000987 atm

Example: 5 millibars = 0.004935 atmospheres

To Technical Atmosphere:

1 mbar = 0.00102 at

Example: 5 millibars = 0.005099 technical atmospheres

To Torr:

1 mbar = 0.750062 Torr

Example: 5 millibars = 3.750308 torr

To Millimeter of Mercury:

1 mbar = 0.750062 mmHg

Example: 5 millibars = 3.750308 millimeters of mercury

To Inch of Mercury:

1 mbar = 0.02953 inHg

Example: 5 millibars = 0.14765 inches of mercury

To Pound per Square Inch:

1 mbar = 0.014504 psi

Example: 5 millibars = 0.072519 pounds per square inch

To Kilopound per Square Inch:

1 mbar = 0.000015 ksi

Example: 5 millibars = 0.000073 kilopounds per square inch

To Kilogram-force per Square Centimeter:

1 mbar = 0.00102 kgf/cm²

Example: 5 millibars = 0.005099 kilograms-force per square centimeter

To Kilogram-force per Square Meter:

1 mbar = 10.197162 kgf/m²

Example: 5 millibars = 50.985811 kilograms-force per square meter

To Millimeter of Water Column:

1 mbar = 10.197162 mmH₂O

Example: 5 millibars = 50.985811 millimeters of water column

To Inch of Water Column:

1 mbar = 0.401463 inH₂O

Example: 5 millibars = 2.007315 inches of water column

Frequently Asked Questions

Yes! 1 mbar = 1 hPa exactly (just different names, same value) Millibar (mbar):

Traditional meteorology unit (1900s-1980s)
Still used: Aviation, maritime, older weather services
Pilots/mariners: "Set altimeter to 1015 millibars" Hectopascal (hPa):
SI-compliant name (1980s-present)
Modern: Weather services worldwide officially use hPa
Scientific: Consistent with SI unit system No conversion needed: 1,013 mbar = 1,013 hPa (identical) Why two names?: Transition to SI units in 1980s. Chose "hectopascal" because 1 hPa = 1 mbar exactly, making transition seamless. Old term persists in aviation/maritime.

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