Digital Audio Bit Rate

Digital audio stores sound as a sequence of samples, and each sample uses a fixed number of bits to represent its amplitude. The total raw bit rate is therefore the number of samples per second, multiplied by the number of bits used for each sample, multiplied again by the number of audio channels being recorded or played. This gives the uncompressed data rate before any file compression or codec overhead is applied.

Use this formula when estimating the storage, bandwidth, or transmission needs of uncompressed audio such as WAV or PCM streams. It is also useful when comparing audio formats or checking whether a network, recorder, or interface can handle a given audio setup.

• Forgetting to multiply by the number of channels for stereo or surround audio
• Using kilobytes instead of bits per second, which makes the result 8 times too small
• Applying this formula to compressed audio formats like MP3 or AAC, where the raw bit rate is not fixed by sample rate alone