De-duplicating redundant data for data aggregation is described herein. In an example, a computing device receives first data identifying first items. The computing device determines that a first data portion and a second data portion indicate that a same item is detected to be within a location. The computing device generates second data by removing the second data portion from the first data. The computing device determines, based on a query to a data store storing previously stored data identifying second items, that (i) a no match exists between the first data portion and the previously stored data, (ii) a match exists between a third data portion of the second data and the previously stored data. The computing device generates a count of items detected within the location by incrementing a previous count based on the no match and by foregoing a count increment based on the match.