Enter the fugacity, pressure, and mole fraction into the calculator to determine the fugacity coefficient.

Fugacity Coefficient Calculator

Direct
Virial (low-P)

Enter any 3 values to calculate the missing one.

Derived Outputs
Base-unit values: f (Pa) —, P (Pa) —
ln(φ): —
Check: f ≈ y × φ × P → —

Related Calculators

Fugacity Coefficient Formula

The following formula is used to calculate the fugacity coefficient for a given set of conditions.

ϕ = f / (P * x)

Variables:

  • ϕ is the fugacity coefficient
  • f is the fugacity
  • P is the pressure
  • x is the mole fraction

To calculate the fugacity coefficient, divide the fugacity by the product of the pressure and mole fraction.

What is a Fugacity Coefficient?

The fugacity coefficient is a dimensionless number that quantifies the deviation of a real gas from ideal gas behavior. It is used in thermodynamics to correct the ideal gas law for real gas effects. The fugacity coefficient is defined as the ratio of the fugacity to the product of the pressure and mole fraction. A fugacity coefficient of 1 indicates ideal gas behavior, while values different from 1 indicate deviations from ideality.

How to Calculate Fugacity Coefficient?

The following steps outline how to calculate the Fugacity Coefficient.


  1. First, determine the fugacity (f).
  2. Next, determine the pressure (P).
  3. Next, determine the mole fraction (x).
  4. Finally, calculate the fugacity coefficient using the formula ϕ = f / (P * x).
  5. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Fugacity (f) = 500 Pa

Pressure (P) = 1000 Pa

Mole Fraction (x) = 0.5