In this work, analytical methods are developed to predict three basic characteristics that quantify the quality of petroleum fuels, such as gasoline and jet fuels. Simple equations have been proposed for the calculations of octane numbers, aniline points, and smoke points of petroleum fuels. Minimum input data for these equations are boiling point and specific gravity; however, when the composition of the mixture in addition to the boiling point is known, better, results can be obtained. Average deviations of about 4-7 for the octane number, 2.5degreesC for aniline point, and 2 mm for smoke point were observed when evaluated with a wide range of data sets with fuels from around the world.