text: The law is expressed as
  where
  * h is the liquid height;
  *  is the surface tension;
  * θ is the contact angle of the liquid on the tube wall;
  * ρ is the mass density (mass per unit volume);
  * r is the tube radius;
  * g is the gravitational acceleration.
  It is only valid if the tube is cylindrical and has a radius (r) smaller than the capillary length (). In terms of the capillary length, the law can be written as