Convert Atmosphere to Kilopascal (atm → kPa)

Converting atmospheres to kilopascals is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in atmospheres

   Start with the number of atmospheres (atm) you want to convert.
2. 2
   Multiply by 101.325

   The conversion factor from atm to kPa is 101.325. Multiply your value by this number.
3. 3
   Read the result in kilopascals

   The result is your value in kilopascals (kPa).

Multiply the value in atmospheres by 101.325. For the reverse direction, multiply by 0.009869.

• ✓1 atm = 101,325 Pa = 1.01325 bar = 14.696 psi.
• ✓Note: atm ≠ bar. Close but not identical.
• ✓Modern SI prefers pascals; atm is a legacy reference.

• ✗Using 1 atm = 1 bar exactly — off by 1.3%.
• ✗Confusing standard atm with technical atmosphere (98,066.5 Pa) or atmosphere-absolute in diving.
• ✗Applying 1 atm outside sea level without correction.

What is the Atmosphere?

The atmosphere equals exactly 101,325 pascals (the average atmospheric pressure at sea level, latitude 45°) and is a reference unit in chemistry, diving, and engineering. Defined for scientific convenience to represent 'standard atmospheric pressure,' it is widely used in chemistry (gas laws, reaction conditions), aviation (cabin pressure relative to ambient), and scuba diving (depth pressure: every 10 m of seawater adds about 1 atm). Standard reference conditions in chemistry often specify 1 atm and 25°C. The atmosphere relates to the pascal (101,325 Pa = 1 atm), the kilopascal (101.325 kPa = 1 atm), the bar (1.01325 bar = 1 atm), the psi (14.696 psi = 1 atm), the torr (760 torr = 1 atm), and the meter of seawater (10.33 mH₂O = 1 atm). The 'technical atmosphere' (1 at = 98.066 kPa = 1 kgf/cm²) is a slightly different historical unit no longer in use.

• Chemistry standard conditions
• Aviation cockpit pressurisation references
• Pressure tank and vessel ratings

What is the Kilopascal?

The kilopascal equals 1,000 pascals and is the standard everyday pressure unit on tire labels (in metric countries), weather forecasts (often expressed as hPa or hectopascals, where 100 kPa = 1 atmosphere), and modern engineering documents. Car tire pressures are typically 200–250 kPa (29–36 psi), medical blood-pressure cuffs measure in mmHg but research increasingly uses kPa, and industrial process pressures are routinely given in kPa. The kilopascal is the most-used pressure unit in metric engineering practice, replacing the older 'kg/cm²' (kilogram-force per square centimeter, ≈ 98 kPa). It relates to the pascal (1,000 Pa = 1 kPa), the megapascal (1,000 kPa = 1 MPa), the bar (1 bar = 100 kPa), the psi (1 psi ≈ 6.895 kPa), and the atmosphere (1 atm ≈ 101.325 kPa). European tire pressure labels universally use kPa or bar.

• Tyre pressures in Canada, Australia
• Engineering pressure specs
• Weather pressure in some contexts