calculating water pressure from water tank Home › Forums › Public Forums › General Plumbing › calculating water pressure from water tank This topic has 1 reply, 2 voices, and was last updated 23 years, 8 months ago by Harold Kestenholz. Viewing 1 reply thread Author Posts 5 Aug 2000 at 2:41 pm #273318 Anonymous What is the formula for calculating water pressure at an outlet from water in a storage tank feet above the outlet? Thanks,Rick G. 5 Aug 2000 at 5:08 pm #287359 Harold KestenholzParticipant Water exerts a pressure of 0.431 pounds for every standing foot of water; so a tank 10 feet above the tap would exert a static pressure of 4.31 lbs. on the tap below. Author Posts Viewing 1 reply thread You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In