How to Use the Audio Bitrate to File Size Calculator
The same song can end up as a very different file size depending on the bitrate used to encode it. Bitrate is the amount of data stored per second of audio, measured in kbps (kilobits per second) โ a higher value means better sound quality, but also a larger file. Enter a bitrate and the track's length in minutes and seconds, and this calculator estimates the resulting file size in MB for compressed audio formats like mp3.
The formula is (bitrate ร length in seconds) รท 8 รท 1024, which converts bits to bytes and then to megabytes. For example, a 3:30 track encoded at 192 kbps comes out to roughly 4.8 MB. Encode that same track at a higher-quality 320 kbps instead, and the file size grows by nearly 1.7 times.
This is handy for estimating the total size of a playlist, or figuring out how many songs will fit on a device with limited storage. Keep in mind this calculation applies to lossy compressed formats like mp3 and AAC โ lossless formats such as FLAC produce much larger files for the same length.
Frequently Asked Questions
Bitrate is the amount of data stored per second of audio. A higher value packs more information into every second, which improves sound quality but also increases the file size proportionally.
On everyday earbuds or speakers, the difference can be hard to notice. On higher-end audio gear or in critical listening situations, many listeners find 320 kbps sounds more natural and detailed. If storage isn't a concern, 320 kbps is the safer choice.