Airtime usage may be used as a factor in controlling network traffic flow to and from client devices via a wireless network interface. Received packets or other data are assigned to a quality of service profile. Additionally, a cost value for communicating the received data is determined at least in part based on an actual or estimated airtime usage for the received packet. The cost value is used to allocate wireless network airtime to data. The allocation of wireless network airtime may be varied dynamically based on operating conditions. The cost value may be based on factors including the airtime used to communicate data; whether the data is a retransmission; and wireless network overhead. The cost value of data may also be different depending on whether the data is being sent from a client device or to a client device.