Bit rate is the number of bits in a time period. Bit rate is usually measured in kilobits per second (abbreviated "kbps" or "kbit/s"). This measurement is generally used to refer to amount of information stored in a lossy, compressed audio format.

To calculate the bit rate, multiply the sample rate and the sample format. For example, the bit rate of an audio CD (705.6 kbps) is the sample rate (44.1 kHz) multiplied by the sample format (16 bits). MP3-format files are commonly encoded with a 128 kbps bit rate.