An airflow control system of a work vehicle includes a controller having a memory and a processor. During an initialization phase, the controller is configured to instruct a blower to operate at an initialization capacity to provide an airflow from an external environment into an interior of a cab of the work vehicle. The controller is also configured to receive a first signal indicative of a pressure within the interior of the cab and to determine a restriction factor based at least in part on the first signal. In addition, during an operation phase, the controller is configured to receive a second signal indicative of the pressure within the interior of the cab and to determine an input flow rate of the airflow from the external environment into the interior of the cab based at least in part on the restriction factor and the second signal.