The Stefan number (St or Ste) is defined as the ratio of sensible heat to latent heat. It is given by the formula The Stefan number (St or Ste) is defined as the ratio of sensible heat to latent heat. It is given by the formula S t e = c p Δ T L , {displaystyle mathrm {Ste} ={frac {c_{p}Delta T}{L}},}