An apparatus and method for metering and treating seed. The apparatus incorporates a belt conveyor or circular conveyor within a housing enabling a low-profile configuration, the conveyor having a plurality of cleats forming a series of separate voids for transporting determinable volumes of seed, and a seed treatment applicator adjacent the conveyor outlet for applying seed treatment to the seed. The apparatus and method allows for the application of seed treatment based on a mass flow calculation derived from the measured volume flow through the apparatus.