Bar to kPa Converter
One bar is exactly 100 kilopascals, so this conversion is a multiplication by 100, which on paper is the decimal point moved two places to the right: 1 bar is 100 kPa, 1.5 bar is 150 kPa, 2.2 bar is 220 kPa, 8 bar is 800 kPa and a 200 bar cylinder is 20,000 kPa. Both units are fixed against the pascal by definition, the bar at 100,000 Pa and the kilopascal at 1,000 Pa, so the factor between them is a whole number that will never be revised and nothing here is rounded away. The pair comes up most often on a tyre placard, where the same pressure is printed as 2.4 bar in one column and 240 kPa in another, and in weather reports, where a kilopascal is ten hectopascals. Type into the From box and the answer updates as you go, shown to twelve significant digits with thousands separators, while the list underneath gives the same pressure in pascals, pounds per square inch and atmospheres at once. This page opens the converter on bar and kilopascals ahead of whatever pair you last used, and it converts units only: whether your reading is gauge or absolute is something the number alone cannot say.
1 bar in every pressure unit
Common questions
- How many kPa are in 1 bar?
- Exactly 100 kPa. The bar is defined as 100,000 pascals and a kilopascal is 1,000 pascals, so one divides into the other cleanly and the conversion is a multiplication by 100 with nothing left over. From there: 0.5 bar is 50 kPa, 0.9 bar is 90 kPa, 1.5 bar is 150 kPa, 2.2 bar is 220 kPa, 3.5 bar is 350 kPa, 10 bar is 1,000 kPa and 200 bar is 20,000 kPa. The headline prints the larger figures with thousands separators, and Copy result puts the plain number on the clipboard, so 200 bar copies as 20000 rather than 20,000.
- What is the formula, and how do I go from kPa back to bar?
- Kilopascals = bar × 100, and bar = kilopascals / 100 in the other direction, which is the same decimal point moved two places the other way: 1 kPa is 0.01 bar, 100 kPa is 1 bar, 220 kPa is 2.2 bar and 350 kPa is 3.5 bar. You do not have to retype anything to reverse it. The Swap units button sits between the two boxes and puts kPa in the From box and bar in the To box, which turns this page into a kPa to bar converter without a reload.
- Is the bar to kilopascal conversion exact, or is it rounded?
- Exact. Neither unit is measured against the other: the bar is defined as 100,000 pascals and the kilopascal is the SI prefix applied to the pascal, so the ratio is a definition rather than an experimental value. Contrast that with pounds per square inch, where 1 bar works out at 14.503773773 psi, a decimal that carries on past what is shown. Answers here print to twelve significant digits, which a factor of 100 never needs, though it does keep the binary arithmetic tidy: 1.01325 bar comes back as a clean 101.325 kPa.
- My tyre placard says 240 kPa. What is that in bar and psi?
- 2.4 bar, and 34.8090570553 psi. Car placards often print two or three of these side by side because pumps are labelled differently by country, and they are the same pressure: 200 kPa is 2 bar, 220 kPa is 2.2 bar and 31.9083023006 psi, 240 kPa is 2.4 bar and 34.8090570553 psi. Put the kPa figure in the From box after pressing Swap units, or type the bar figure directly and read the kPa and psi answers off the list below the headline.
- What else does it show me besides kilopascals?
- Every other unit in the pressure category at the same time, worked out from the value you typed rather than one target at a time. For 1 bar the list reads 100,000 Pa, 100 kPa, 14.503773773 psi and 0.986923266716 atm, and for 200 bar it reads 20,000,000 Pa, 20,000 kPa, 2,900.7547546 psi and 197.384653343 atm. Millimetres of mercury stay out of the way until you tick the uncommon units switch in the readout strip, labelled Show 1 more, where 1 bar reads 750.061575846 mmHg.
- How do I convert millibars, hectopascals or megapascals here?
- By moving the decimal point, since none of the three is a separate entry in this list. A millibar and a hectopascal are the same size, one tenth of a kilopascal, so kPa × 10 gives hPa and bar × 1,000 gives mbar: a sea level reading of 1,013.25 mbar is 1.01325 bar, which this page converts to 101.325 kPa, and that is 1,013.25 hPa again. A megapascal is 1,000 kPa, so divide the answer by a thousand: 10 bar is 1,000 kPa or 1 MPa, and 200 bar is 20,000 kPa or 20 MPa.
- Is one bar the same as one atmosphere?
- No, it is about 1.3 percent below it. A standard atmosphere is defined as exactly 101,325 pascals, which is 101.325 kPa, so 1 bar is 0.986923266716 atm and 1 atm is 1.01325 bar. Type 1.01325 with bar selected and the answer reads 101.325 kPa with exactly 1 atm in the list under it. Close enough to trade the words in conversation, far enough apart to matter on a gauge you have calibrated.
- Does it know whether my figure is gauge or absolute pressure?
- No, and it never guesses: it changes units and leaves the number alone, so it will not add or subtract an atmosphere for you. A tyre at 2.2 bar on the gauge is 220 kPa above the surrounding air, and the same tyre stated absolutely is about 3.21325 bar, or 321.325 kPa. Decide which convention your reading uses before converting it. Negative figures are accepted for the same reason, so a vacuum reading of -0.5 bar gauge comes back as -50 kPa.
- Why does the page open on bar and kPa when I last converted something else?
- Because a page that names a pair should be showing that pair when it loads. This one sets bar and kilopascals on arrival, ahead of the units the converter last remembered, and it leaves that memory alone: go back to /unit-converter and it is still on the pair you left there. The number you last typed does travel with you, since it is usually the figure you are still working on. Anything that is not a number, such as 2.2 bar typed with its unit, leaves the headline reading Ready and prints a line saying what a number here looks like; a comma is treated as a thousands separator, so 1,013.25 is read as 1013.25.
Conversion factors are the exact legal definitions where one exists. An inch is exactly 2.54 cm and a pound exactly 0.45359237 kg, so those conversions are exact rather than approximate. Temperature uses offsets rather than factors, and that is shown in the working.