Convert Millibar to Pound per square inch
1 millibar = 0.01450377 pound per square inch (psi). For example, 10 millibar = 0.1450377 pound per square inch and 100 millibar = 1.450377 pound per square inch. Type any value below to convert millibar to pound per square inch both ways — it runs entirely in your browser.
Quick answer: Millibar to Pound per square inch
1 Millibar = 0.01450377 Pound per square inch (mbar → psi). To convert millibar to pound per square inch, multiply by 0.01450377. To convert pound per square inch to millibar, multiply by 68.94757. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common millibar-to-pound per square inch questions.
How to convert Millibar to Pound per square inch
To convert millibar to pound per square inch, multiply the number of millibar by the conversion factor 0.01450377, because 1 mbar = 0.01450377 psi. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 psi = 68.94757 mbar, so you divide by 0.01450377 (or multiply by 68.94757) to turn pound per square inch back into millibar.
psi = mbar × 0.01450377 ·
mbar = psi × 68.94757
- Write down the value you want to convert, in millibar.
- Multiply it by 0.01450377.
- The result is the same area/length/quantity expressed in pound per square inch.
Millibar to Pound per square inch — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 millibar is 0.07251887 pound per square inch because 5 mbar × 0.01450377 = 0.07251887 psi.
| Millibar | Calculation | Pound per square inch |
|---|---|---|
| 1 mbar | 1 mbar × 0.01450377 = 0.01450377 psi | 0.01450377 psi |
| 2 mbar | 2 mbar × 0.01450377 = 0.02900755 psi | 0.02900755 psi |
| 3 mbar | 3 mbar × 0.01450377 = 0.04351132 psi | 0.04351132 psi |
| 5 mbar | 5 mbar × 0.01450377 = 0.07251887 psi | 0.07251887 psi |
| 7 mbar | 7 mbar × 0.01450377 = 0.1015264 psi | 0.1015264 psi |
| 10 mbar | 10 mbar × 0.01450377 = 0.1450377 psi | 0.1450377 psi |
| 12 mbar | 12 mbar × 0.01450377 = 0.1740453 psi | 0.1740453 psi |
| 15 mbar | 15 mbar × 0.01450377 = 0.2175566 psi | 0.2175566 psi |
| 20 mbar | 20 mbar × 0.01450377 = 0.2900755 psi | 0.2900755 psi |
| 25 mbar | 25 mbar × 0.01450377 = 0.3625943 psi | 0.3625943 psi |
| 50 mbar | 50 mbar × 0.01450377 = 0.7251887 psi | 0.7251887 psi |
| 100 mbar | 100 mbar × 0.01450377 = 1.450377 psi | 1.450377 psi |
Common Millibar to Pound per square inch conversions
These are the millibar-to-pound per square inch values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 millibar = 0.01450377 pound per square inch
- 2 millibar = 0.02900755 pound per square inch
- 2.5 millibar = 0.03625943 pound per square inch
- 3 millibar = 0.04351132 pound per square inch
- 4 millibar = 0.0580151 pound per square inch
- 5 millibar = 0.07251887 pound per square inch
- 6 millibar = 0.08702264 pound per square inch
- 7 millibar = 0.1015264 pound per square inch
- 8 millibar = 0.1160302 pound per square inch
- 9 millibar = 0.130534 pound per square inch
- 10 millibar = 0.1450377 pound per square inch
- 12 millibar = 0.1740453 pound per square inch
- 15 millibar = 0.2175566 pound per square inch
- 20 millibar = 0.2900755 pound per square inch
- 25 millibar = 0.3625943 pound per square inch
- 30 millibar = 0.4351132 pound per square inch
- 50 millibar = 0.7251887 pound per square inch
- 75 millibar = 1.087783 pound per square inch
- 100 millibar = 1.450377 pound per square inch
- 200 millibar = 2.900755 pound per square inch
- 500 millibar = 7.251887 pound per square inch
- 1000 millibar = 14.50377 pound per square inch
Millibar to Pound per square inch conversion chart (both directions)
The chart below converts millibar to pound per square inch and pound per square inch to millibar side by side, so it works whichever way you need. 1 millibar = 0.01450377 pound per square inch, and 1 pound per square inch = 68.94757 millibar.
| Millibar → Pound per square inch | Pound per square inch → Millibar |
|---|---|
| 0.25 mbar = 0.003625943 psi | 0.25 psi = 17.23689 mbar |
| 0.5 mbar = 0.007251887 psi | 0.5 psi = 34.47379 mbar |
| 1 mbar = 0.01450377 psi | 1 psi = 68.94757 mbar |
| 2 mbar = 0.02900755 psi | 2 psi = 137.8951 mbar |
| 3 mbar = 0.04351132 psi | 3 psi = 206.8427 mbar |
| 4 mbar = 0.0580151 psi | 4 psi = 275.7903 mbar |
| 5 mbar = 0.07251887 psi | 5 psi = 344.7379 mbar |
| 6 mbar = 0.08702264 psi | 6 psi = 413.6854 mbar |
| 7 mbar = 0.1015264 psi | 7 psi = 482.633 mbar |
| 8 mbar = 0.1160302 psi | 8 psi = 551.5806 mbar |
| 9 mbar = 0.130534 psi | 9 psi = 620.5282 mbar |
| 10 mbar = 0.1450377 psi | 10 psi = 689.4757 mbar |
| 12 mbar = 0.1740453 psi | 12 psi = 827.3709 mbar |
| 15 mbar = 0.2175566 psi | 15 psi = 1,034.214 mbar |
| 20 mbar = 0.2900755 psi | 20 psi = 1,378.951 mbar |
| 25 mbar = 0.3625943 psi | 25 psi = 1,723.689 mbar |
| 30 mbar = 0.4351132 psi | 30 psi = 2,068.427 mbar |
| 40 mbar = 0.580151 psi | 40 psi = 2,757.903 mbar |
| 50 mbar = 0.7251887 psi | 50 psi = 3,447.379 mbar |
| 75 mbar = 1.087783 psi | 75 psi = 5,171.068 mbar |
| 100 mbar = 1.450377 psi | 100 psi = 6,894.757 mbar |
| 150 mbar = 2.175566 psi | 150 psi = 10,342.14 mbar |
| 200 mbar = 2.900755 psi | 200 psi = 13,789.51 mbar |
| 250 mbar = 3.625943 psi | 250 psi = 17,236.89 mbar |
| 500 mbar = 7.251887 psi | 500 psi = 34,473.79 mbar |
| 1000 mbar = 14.50377 psi | 1000 psi = 68,947.57 mbar |
Millibar vs Pound per square inch: which is bigger?
A pound per square inch is the larger unit: one pound per square inch equals 68.94757 millibars. Put another way, you need 68.94757 millibars to make a single pound per square inch.
What is a Millibar? History, origin and usage
The bar and its millibar subdivision were proposed by the Norwegian meteorologist Vilhelm Bjerknes in the early twentieth century, as part of the same push that gave us modern weather fronts. He wanted a pressure unit sized to the atmosphere itself rather than to a mercury column, and the millibar was adopted internationally for weather work in 1929.
Millibars are still used for atmospheric pressure, especially in older records, in shipping and in some national forecasts. They also appear on vacuum equipment and altimeter settings. Because a millibar and a hectopascal are the same size, the two are freely interchangeable.
A millibar is one thousandth of a bar, or 100 pascals. The lowest sea-level pressure ever measured in a tropical cyclone was 870 mbar, in Typhoon Tip in 1979 — a reading that would be written identically as 870 hPa.
What is a Pound per square inch? History, origin and usage
Pounds per square inch grew directly out of the steam age: boiler safety valves were rated by how many pounds of weight it took to hold them shut over a known area, and the unit survived into every later technology that Britain and the United States industrialised. It never went through a formal international definition of its own — instead it became exact in 1959, when the yard-and-pound agreement fixed the pound and the inch exactly, and again through the fixing of standard gravity, which pins down what a "pound of force" means.
Psi is the standard pressure unit in the United States and remains widely understood in Britain, India and elsewhere: tyre pressures, air compressors, pressure washers, water mains, hydraulic lines and scuba tanks. Car tyres are commonly inflated to around 30 to 35 psi.
Psi is exactly defined but its value in pascals is a decimal that repeats forever, so any written figure is necessarily rounded somewhere. Gauges usually read gauge pressure — the amount above surrounding air — which is why a flat tyre reads zero rather than about 14.7.
Convert 1 Millibar to other units
It can help to see a millibar next to the other units it is commonly compared with. One millibar (mbar) is equal to:
| 1 Millibar equals | Unit |
|---|---|
| 100 Pa | Pascal |
| 1 hPa | Hectopascal |
| 0.1 kPa | Kilopascal |
| 0.0001 MPa | Megapascal |
| 0.001 bar | Bar |
| 0.0009869233 atm | Standard atmosphere |
| 0.7500617 Torr | Torr |
| 0.7500616 mmHg | Millimetre of mercury |
| 0.02952998 inHg | Inch of mercury |
| 10.19716 mmH₂O | Millimetre of water |
| 0.4014631 inH₂O | Inch of water |
| 0.01450377 psi | Pound per square inch |
| 0.001019716 kgf/cm² | Kilogram-force per square centimetre |
Convert 1 Pound per square inch to other units
One pound per square inch (psi) is equal to:
| 1 Pound per square inch equals | Unit |
|---|---|
| 6,894.757 Pa | Pascal |
| 68.94757 hPa | Hectopascal |
| 6.894757 kPa | Kilopascal |
| 0.006894757 MPa | Megapascal |
| 68.94757 mbar | Millibar |
| 0.06894757 bar | Bar |
| 0.06804596 atm | Standard atmosphere |
| 51.71493 Torr | Torr |
| 51.71493 mmHg | Millimetre of mercury |
| 2.036021 inHg | Inch of mercury |
| 703.0696 mmH₂O | Millimetre of water |
| 27.6799 inH₂O | Inch of water |
| 0.07030696 kgf/cm² | Kilogram-force per square centimetre |
Tips for converting Millibar to Pound per square inch
- To go from millibar to pound per square inch, multiply by 0.01450377; to go back, divide by 0.01450377 (or multiply by 68.94757).
- For a quick mental estimate, remember that 1 millibar ≈ 0.01450377 pound per square inch, so 10 millibar ≈ 0.1450377 pound per square inch.
- The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
- Both fields update live as you type — change either side to convert in that direction.
How to use this Millibar to Pound per square inch converter
Type a number into the Millibar field and the equivalent in Pound per square inch appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Pound per square inch field to convert the other way (pound per square inch to millibar). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.
Accuracy and method
Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 mbar = 0.01450377 psi), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for millibar-to-pound per square inch conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.
Sources
- NIST Special Publication 811 — Guide for the Use of the SI — publishes the exact metric equivalents of the customary pressure units. A psi is one pound of force over one square inch, and the 1959 international yard-and-pound agreement fixes the pound at exactly 0.453 592 37 kilogram and the inch at exactly 0.0254 metre, while standard gravity is fixed at exactly 9.806 65 m/s² — so psi, inches of mercury and inches of water are defined exactly rather than measured.
- BIPM — The International System of Units (SI Brochure) — the defining document for the SI, published by the International Bureau of Weights and Measures. It fixes the base unit that this conversion resolves to, which is why the factor here can be exact rather than approximate.
Pressure factors here come from fixed definitions, anchored to the pascal: a bar is exactly 100,000 Pa, one atmosphere is exactly 101,325 Pa, a torr is exactly a 760th of an atmosphere, and psi is built from the exact pound and the exact inch. Two of them — psi and the torr — work out to decimals that repeat forever, so where a number is shown rounded it is marked, not quietly trimmed.
Frequently asked questions
- How many pound per square inch are in 1 millibar?
- 1 millibar = 0.01450377 pound per square inch (psi). To convert any number of millibar to pound per square inch, multiply by 0.01450377.
- How do I convert millibar to pound per square inch?
- Multiply the number of millibar by 0.01450377. For example, 10 millibar = 10 × 0.01450377 = 0.1450377 pound per square inch, and 25 millibar = 0.3625943 pound per square inch.
- How many millibar are in 1 pound per square inch?
- 1 pound per square inch = 68.94757 millibar. So to convert pound per square inch back to millibar, multiply by 68.94757.
- What is the formula to convert millibar to pound per square inch?
- pound per square inch = millibar × 0.01450377. The reverse formula is millibar = pound per square inch × 68.94757.
- How much is 100 millibar in pound per square inch?
- 100 millibar = 1.450377 pound per square inch. (And 1000 millibar = 14.50377 pound per square inch.)
- Which is bigger, a millibar or a pound per square inch?
- A pound per square inch is larger: 1 pound per square inch = 68.94757 millibar.
- Is this millibar to pound per square inch converter accurate?
- Yes — every value is computed from the exact 0.01450377 psi per mbar factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert pound per square inch to millibar too?
- Yes. The converter works both ways — enter a value in either field. 1 pound per square inch = 68.94757 millibar.