The unit symbol "atm" refers to units of atmospheric pressure found at sea level on the planet earth, and "kPa," or kilopascals, are smaller units of pressure, each of which is 1000 pascals. To convert from atm to kPa, you would need a calculator for precise measurements, or you can make a close estimate without one.
- Understand the conversion
Both atm and kPa describe force applied over a particular area. They essentially measure the same thing but with different units. Only one conversion operation is necessary. 1 atm is equal to 101.325 kPa. This means that 1 atm is also equal to 1.013 bars and 101325.0 pa. For estimates, remember that there are 100 kilopascals in each unit of atmospheric pressure.
- Multiply by the conversion rate
If you have 1.25 atm, then the equivalent in kPa is equal to 1.25 * 101.325. Use the fraction 101.325kPa / 1atm to cancel the atm units so that only kPa remains. 1,25atm * 101.325kPa / 1atm = 126.656kPa To estimate, use 100, as in 1,25atm * 100 / 1atm = 125kPa, which is close to 126.656kpa. To convert from kpa to atm, multiply by the reciprocal of 101.325, which equals 1/101/325 or 0.00987.
- Check your answer
You can check your answer by performing the operation in reverse to get back to the original number. Also, check to make sure that there is a little more than 100kPa per every atm.