How to Convert Absolute PSI to Feet in Altitude
- 1). Convert your absolute psi to the standard unit for measuring atmospheric pressure (atm) by dividing the absolute psi by 14.696. For example, an absolute psi of 13 is equivalent to approximately .8846 atm: 13 / 14.696 = 0.8846.
- 2). Find the natural log (ln) of the atmospheric pressure using a scientific calculator with the natural log function. For example, if the atmospheric pressure is 0.8846 atm, your answer will be approximately -0.1227: ln(0.8846) = -0.1227.
- 3). Divide the value found in Step 2 by -0.012 to calculate the altitude, in hundreds of meters. For example, -0.1227 divided by -0.012 equals 10.225. Therefore, your altitude is 1,022.5 meters above sea level.
- 4). Multiply your altitude, in meters, by 3.28 to convert the altitude from meters into feet units. For example, 1,022.5 meters would be equivalent to 3,353.8 feet above sea level: 1,022.5 x 3.28 = 3,353.8.