A mechanism is described for determining an amount of item that remains in the possession of a consumer for an automatic item subscription system, as well as a subsequent replacement date for that item. The remaining item amount may be determined from a consumption rate that is calculated from a number of factors. In some embodiments, the consumption rate may be based on cluster data or data representing trends related to the underlying item. As the consumption rate for an item changes, the replacement date may be dynamically updated to reflect the change in the consumption rate.