Sliding of contents during past earthquakes has caused injury, disruptions, and damage. As such, equations to predict the maximum sliding displacement of the contents are required to include its effect in building performance assessments. This paper examines six different prediction equations, including a new equation derived in this paper based on the first sliding excursion of contents subjected to sinusoidal floor motion. The accuracy of these equations was assessed by comparing the ratio of the maximum sliding displacement obtained from an analytical study to that from the prediction. The analytical study consisted of modeling the sliding movement of contents in three elastically responding 5-story buildings of varying periods subjected to the entire set of 3,225 unscaled ground motion records available on the Pacific Earthquake Engineering Research Center’s database. It was found that the prediction equation derived in this study had the best fit of all prediction equations considered, with the median sum of squared relative error between 4 and 6 times smaller than the next best prediction.