What determines audio file size?
Digital audio stores measurements of a waveform. Sample rate controls how many measurements are stored each second, bit depth controls how many bits each sample uses, and the channel count multiplies that stream. Those three values determine the size of uncompressed PCM audio such as WAV or AIFF. A compressed format such as MP3, AAC, or Opus is usually estimated from its encoded bitrate instead.
Choosing realistic settings
For music delivery, 44.1 kHz is common; video workflows often use 48 kHz. A 24-bit recording gives useful production headroom, while a final consumer file may be 16-bit or compressed. Enter the actual encoded bitrate when planning compressed storage because the PCM settings do not determine an MP3 or AAC file's final size.
Planning storage and transfers
Multiply one file by the number of songs, episodes, stems, or sessions you expect to retain. Keep working files, exports, backups, artwork, and project data in the plan. Network transfer time also depends on overhead and real throughput, so a connection's advertised speed should not be treated as a guaranteed sustained rate.
Limits of the estimate
Container headers and metadata add a small amount. Variable-bitrate encoders change bitrate with the signal, lossless codecs vary with compressibility, and multitrack projects include more than the final mix. Use the result as a capacity estimate and confirm critical deliveries with the exported file.
How the calculation works
PCM size equals duration × sample rate × bit depth × channel count. Compressed size uses duration × bitrate.
