A method for measuring airflow for a plurality of computing devices may include characterizing the fan performance of a selected computing device of the plurality of computing devices to provide characterized RPM information. Each of the computing devices may include a cooling fan configured to exhaust heat into a hot aisle. Each cooling fan may include a rotor and a tachometer. The method may also include connecting the computing devices via a network, distributing computing workloads to the plurality of computing devices, and/or performing work on the computing workloads on the plurality of computing devices. Additionally, the method may include reading RPM information from the selected computing device's fan's tachometer and/or comparing the read RPM information with the characterized RPM information to determine a backpressure value for the selected computing device. The power to the selected computing device's fan may be reduced prior to reading the RPM information.