Vapor Pressure of Water Calculator

Vapor pressure is the pressure exerted by a vapor that is in thermodynamic equilibrium with its condensed phases (solid or liquid) in a closed system at a given temperature. It represents the tendency of a liquid to evaporate at a specific temperature.

Yes, vapor pressure increases exponentially with temperature. As temperature rises, more molecules have enough kinetic energy to escape from the liquid phase, resulting in higher vapor pressure.

Enter 80 in the temperature field and select your desired pressure unit. The calculator will use multiple formulas including Antoine, Magnus, Tetens, Buck, and Simple equations to provide accurate vapor pressure values.

The Antoine equation is generally considered the most accurate for vapor pressure calculations over moderate temperature ranges. However, different formulas may be more suitable for specific temperature ranges or applications.

Theoretically, vapor pressure approaches zero only at absolute zero temperature (-273.15°C). At any temperature above absolute zero, water molecules have some kinetic energy and vapor pressure exists, though it may be extremely small at very low temperatures.

Water vapor pressure is crucial in meteorology for weather prediction, in engineering for steam systems design, in chemistry for distillation processes, and in many industrial applications involving evaporation and condensation.

While temperature is the primary factor, vapor pressure can also be influenced by the presence of dissolved substances (which lower vapor pressure), atmospheric pressure, and the purity of the liquid.

Each formula has its optimal temperature range. Antoine is most accurate for moderate temperatures, Magnus works well for meteorological applications, Tetens is good for atmospheric conditions, Buck is accurate over wide ranges, and the Simple formula provides quick approximations.