Converters
Convert pressure between pascals, kilopascals, bar, PSI, and atmospheres.
Enter your numbers to see the answer.
Pressure converter guide
The pressure converter handles pascals, kilopascals, bar, pounds per square inch, and standard atmospheres. The pascal, one newton per square meter, is the SI unit, and every factor is an exact definition: a bar is 100,000 Pa, a standard atmosphere is 101,325 Pa, and a psi is one pound-force (4.4482216152605 N) on one square inch (0.00064516 m²), which is 6,894.757293 Pa. The tool converts through pascals and lists all five units for every entry. Use it for tire pressures posted in psi on a car with a kPa door label, dive cylinders in bar, weather reports in hPa or millibars, and pump or compressor ratings in any of the five. The converter changes only the unit, not the reference point, so read the units section for the gauge-versus-absolute distinction before comparing a tire gauge with a barometer.
Pressure (to) = pressure (from) × pascals per from-unit ÷ pascals per to-unit. Factors (Pa): pascal 1, kilopascal 1,000, bar 100,000, psi 6,894.757293168, atm 101,325.
Worked example with the defaults: 1 bar to psi. First to pascals: 1 × 100,000 = 100,000 Pa. Then divide by the pascals in a psi: 100,000 ÷ 6,894.757293 = 14.50 psi, which the converter displays as 14.5 psi. The detail rows show 100 kPa and 100,000 ÷ 101,325 = 0.99 atm. A tire inflated to 35 psi is 35 × 6,894.757 = 241,316.5 Pa, or 241.32 kPa and 2.41 bar; a 200 bar scuba cylinder is 200 × 14.5038 = 2,900.75 psi.
Enter the pressure as a decimal in Pa, kPa, bar, psi, or atm. Hectopascals and millibars are each 100 Pa, so a forecast of 1,013 hPa is 101.3 kPa or 1.013 bar. Megapascals multiply by 1,000 to kPa. Inches of mercury (3,386.39 Pa) and mmHg or torr (133.322 Pa) are not offered; convert them to pascals before entry. Results show two decimals, so small differences in psi may need the kPa row.
Unit conversion is exact when the conversion factor is exact, so the only real uncertainty here is rounding and the precision of your input. Where a unit has more than one definition — US versus imperial measures, or short versus metric tons — the wrong variant produces a plausible-looking but wrong answer. The units note above states which definition this page uses. On this page the figure rests entirely on value, from and to, so start there if the pressure converter returns something you did not expect.
Good to know: bar, atm, and 100 kPa are close but not equal. A bar is 0.987 atm, so treating them as identical is a 1.3% error, which is harmless for tires but not for gas-law calculations. Tire gauges read gauge pressure, above the surrounding atmosphere, while barometers and many scientific tables use absolute pressure; add about 101 kPa to a gauge reading to compare them. The converter treats psig and psia the same, so keep the two apart yourself.
Conversion results use stated mathematical factors and display precision. For regulated, medical, engineering, or contractual work, confirm the required standard and precision.
Sources
How it works
Convert pressure between pascals, kilopascals, bar, PSI, and atmospheres. This tool explains the calculation so you can adjust the assumptions to match your situation.
Worked example
With Value = 1 · From = bar · To = psi → 14.5 psi (1 bar converted to psi). Change an input above and this example updates with your numbers.
Common questions
14.504 psi, from 100,000 ÷ 6,894.757. So 2 bar is 29.01 psi, 2.5 bar is 36.26 psi, and 3 bar is 43.51 psi. In the other direction, 1 psi is 0.06895 bar, or 6.895 kPa.
A standard atmosphere is exactly 101.325 kPa, which is 14.696 psi or 1.01325 bar. It is the defined sea-level reference pressure; a real barometer reading varies by a few percent either side of it with the weather.
35 psi is 2.41 bar and 241.32 kPa. Other common tire pressures: 30 psi is 2.07 bar (206.84 kPa), 32 psi is 2.21 bar (220.63 kPa), and 40 psi is 2.76 bar (275.79 kPa). Check the placard inside the driver’s door for the specified value.
No. One bar is exactly 100 kPa, so kPa = bar × 100. A 220 kPa tire label means 2.2 bar or 31.91 psi. Weather services quote hectopascals; 1,000 hPa is 100 kPa or 1 bar.
psig is gauge pressure, measured above local atmospheric pressure; psia is absolute, measured above a vacuum. A tire at 32 psig is about 46.7 psia at sea level. The converter changes units only, so keep gauge and absolute readings separate before comparing them.