Technologies are described for performing equation-based rate control using delay. For example, an observed network data rate and a network delay can be obtained for a network communication. A target network data rate can be calculated using the observed network data rate and the network delay. The target network data rate is calculated using an equation-based approach. For example, the equation-based rate control can set the target network data rate to a value that is directly proportional to the observed network data rate and inversely related to the network delay. The target network data rate is used to set the bitrate for the network communication.