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To convert a pressure from millibar (mbar) to pascals (Pa), multiply by 100.
The factor is exact and definitional: one bar is 100,000 Pa, so a thousandth of it is 100 Pa. This also makes the millibar identical to the hectopascal — 1 mbar = 1 hPa, no rounding involved — which is why weather charts switched labels from mbar to hPa decades ago without a single number changing.
A weather station reports sea-level pressure of 1,013.25 mbar and a lab calculation needs SI units:
That is the standard atmosphere, exactly.
| mbar | Pa |
|---|---|
| 1 | 100 |
| 10 | 1,000 |
| 50 | 5,000 |
| 100 | 10,000 |
| 250 | 25,000 |
| 500 | 50,000 |
| 1,000 | 100,000 |
| 1,013.25 | 101,325 |
The millibar owes its career to two communities at opposite ends of the pressure scale. Meteorology adopted it because atmospheric pressure lands in a tidy range around 1,000 mbar — lows in the 950s, highs in the 1,040s — and although official charts now say hPa, aviation weather (QNH altimeter settings), marine forecasts and hurricane reporting still speak millibars; a storm's central pressure of "915 mb" is 91,500 Pa. Vacuum technology adopted it from the other side: pump specifications and process recipes across European industry quote chamber pressures in mbar, running from atmospheric down to 10⁻⁹ mbar and below, where the pascal equivalents (10⁻⁷ Pa) are just as convenient but historically less used in datasheets.
The conversion itself is exact, so the only real pitfall is neighborly confusion between the units this page does not convert: a millibar is not a mmHg (1 mbar = 0.750 mmHg) and not a psi. Weather reports in North America compound the risk by quoting inches of mercury to the public and millibars to aviation — 29.92 inHg and 1,013 mbar are the same standard atmosphere wearing two costumes.
How many millibar are in one pascal? One pascal (Pa) contains 0.01 millibar (mbar) — the inverse of the factor above. Multiplying by 100 takes you from millibar to pascals; multiplying by 0.01 brings you back.
Put in words: one millibar equals 100 pascals, so the millibar is the larger unit of this pair. Converting between them never changes the amount of pressure being measured — only the size of the unit you count it in.
A millibar (mbar) is a metric unit used to measure atmospheric pressure.
It's most commonly used in weather forecasting and reporting.
(Technically, one millibar is equal to 0.1 kilopascal, or kPa).
Meteorologists use millibars as the primary unit to measure and report atmospheric pressure.
On weather maps, you'll see lines called isobars, which connect areas of equal pressure, drawn in millibar intervals.
Standard atmospheric pressure at sea level is about 1013 mbar.
This number is a key benchmark for weather conditions:
Yes, for all practical purposes, a millibar (mbar) and a hectopascal (hPa) are the same.
The two units are used interchangeably.
The conversion is simple: 1 mbar = 1 hPa.
While you'll still see millibars in public weather reports (especially in the U.S.), the hectopascal is the preferred SI (International System of Units) unit for global scientific consistency.
A barometer measures barometric pressure—the weight of the air above you—using millibars.
Watching the change in this reading is key to predicting the weather:
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.
Here are some quick reference conversions from millibar (mbar) to pascal (Pa):
| millibar | pascals |
|---|---|
| 0.000001 mbar | 10-4 Pa |
| 0.001 mbar | 0.1 Pa |
| 0.1 mbar | 10 Pa |
| 1 mbar | 100 Pa |
| 2 mbar | 200 Pa |
| 3 mbar | 300 Pa |
| 4 mbar | 400 Pa |
| 5 mbar | 500 Pa |
| 6 mbar | 600 Pa |
| 7 mbar | 700 Pa |
| 8 mbar | 800 Pa |
| 9 mbar | 900 Pa |
| 10 mbar | 1000 Pa |
| 20 mbar | 2000 Pa |
| 30 mbar | 3000 Pa |
| 40 mbar | 4000 Pa |
| 50 mbar | 5000 Pa |
| 100 mbar | 104 Pa |
| 1000 mbar | 105 Pa |
| 10000 mbar | 106 Pa |
Engineering datasheets across Europe write millibar to pascal several different ways. The calculation is the same in every one of them.
| Language | Written as | Unit names |
|---|---|---|
| French | mbar en Pa | millibar → pascal |
| Spanish | mbar a Pa | milibar → pascal |
| Dutch | mbar naar Pa | millibar → pascal |
| German | mbar in Pa | Millibar → Pascal |
| Polish | mbar na Pa | milibar → paskal |
For all Pressure converters, choose units using the From/To dropdowns above.