Audio File Size Calculator

About this calculator

This calculator estimates a compressed audio file's size using size = (bitrate × duration) / 8, converting bits per second to bytes, since bitrate for formats like MP3 and AAC is specified as the number of bits used to encode each second of audio regardless of the file's sample rate or bit depth. A higher bitrate spends more bits per second on the encoding, producing better fidelity at the cost of a larger file — the trade-off every lossy audio format is built around.

Podcasters and musicians use this before exporting to predict whether a file will fit a hosting platform's upload limit or a client's email attachment size, and audio engineers use it to plan storage and bandwidth for a batch of episodes or tracks before committing to a bitrate for the whole project.