This work presents in the first section the procedure for the measurement and calibration of a smooth spheroidal tank using API Standard 2552 - ASTM D 1408-65 and the Liquid Calibration or API Standard 2555 - ASTM D 1406. We developed the gage table using the API Standard 2552 and the other gage table obtained for a company of calibration of tanks using Liquid Calibration. Calculations were made for a tank of Refinería La Libertad. The final section we concluded that the precision of results are usually of various factors, which affect the tank capacity table. Also presented is an analysis of the comparison with results from two gages tables. Comparison of the curves shows the difference of partial and total volumes of the tank.