# Atmospheric pressure vs. boiling point equation

What is the relationship between the pressure of water and its boiling point? I am aware that a substance boils as soon as its vapor pressure equals that of the surrounding air. I have researched extensively and the best I could come come up with was rearranging the Goff-Gratch or Arden-Buck equations for temperature. While this does give me accurate approximations, I wonder why no clean formula exists that utilises physical constants, as exist for almost all other relationships in physics. Surely some equation like $$F=ma$$ or $$PV=nRT$$ must exist also for this relationship, and not just a function matched to experimental data? I appreciate any help.

$$PV=nRT$$ is an approximation that is approached by many gases at lower pressures and higher temperatures because the interactions between particles is reduced (and approaches zero).