VaporCalc & AntoineVP

Vapor pressure calculator and grapher for over 10,000 organic and inorganic chemicals at your fingertips.

An educational/scientific application for macOS* iPad and iPhone.

One time download cost of $1.99 for macOS or iPad
One time download cost of $0.99 for iPhone**

Vapor pressure is a fundamental concept in thermodynamics and has various practical applications across different fields. Some common uses for vapor pressure include:

  • Understanding phase transitions, such as the boiling point of a liquid. When the vapor pressure of a liquid becomes equal to the atmospheric pressure, the liquid will start to boil,
  • Meteorology to determine the amount of moisture in the air,
  • Understand the behavior of chemicals and their evaporation rates, which is important in processes like distillation, solvent recovery, and separation techniques,
  • Relevant in fuel systems, where it affects the volatility and evaporation of gasoline and other fuels, influencing engine performance and emissions,
  • Significant in climate science as it affects the greenhouse effect,
  • Distillation of substances, as it allows the separation of components based on their different vapor pressures,
  • Important in design of HVAC and heat pump systems, where the vapor pressure of the refrigerant must be carefully controlled.
Vapor pressure plot for freon 134A. Blue vertical line may be dragged across plot to update temperature and pressure.

*Intel and Silicon processors running macOS 13 and later and iOS 16 and later.
**iPhone version does NOT have vapor pressure versus temperature plotting capability.

© Steven W. Sharpe