Initially, the ebulliometer degree is calculated:

ebulliometer degree = calibration - reading

This essentially yields the number of degrees below the boiling point of water, at which the sample is boiling.

Next, a polynomial expression generated from a large data set is used to give the alcohol (% by volume):

alcohol = 0.0002590805845 * d⁴ - 0.0006404605357 * d³ + 0.001926392743 * d² + 1.364664067 * d - 1.29216576

Where d = the ebulliometer degree.