Find the information on the number of stories a building has, as well as the seismic weight of each floor. This will allow for the calculation of the seismic story force.
Find the base dimensions of the building (length and width). The base dimensions of the building will determine its stability.
Find out the types of material that the building is made out of. Primarily this should be what kind of frames the building has, as well as what the walls are constructed from. Additionally, the kind of hazard importance the building was built to will also be important. This information will go into the appropriate spots of the calculator.
Find what kind of soil the building is primarily built upon. The density and amount of rock in the soil will determine how stable the ground the structure is built upon is.
Find the major city that the structure is built near. This will determine the seismic forces that may act on the structure.
Take all of the numerical data you have accumulated and enter it into the appropriate places of the calculator to find the seismic load. The calculator can be updated in order to see what effects various variables may have on it.