Abstract: An air cart having a modular metering system. The modular metering system includes a plurality of meter modules disposed laterally adjacent to one another in a metering bank. Each of the meter modules is independently removable from the metering bank. Each meter module includes a metering mechanism rotatable about a longitudinal axis disposed generally parallel with a forward direction of travel of the air cart. The metering mechanism is in communication with a supply of product held within a tank. As the metering mechanisms rotates about its longitudinal axis, the product is metered by the metering mechanism into an air tube associated with each of the plurality of meter modules. An air stream provided by at least one fan carries the metered product through the air tubes.