Export an audio file to MP3, estimate its size and check the result. A practical guide without file uploads.
Open your audio in a compatible audio editor or converter and use its export function to choose MP3. This page is an instruction guide; it does not upload or convert a file in your browser. Keep an untouched copy of the source.
Bitrate influences both file size and lossy compression. Speech and music have different needs. If a target service specifies channels, sample rate or a bitrate range, follow those requirements rather than repeatedly converting an already compressed file.
Approximate size in bytes is bitrate in bits per second × duration in seconds / 8. At 128 kbit/s, 180 seconds is about 2.88 MB before small metadata overhead. Variable bitrate will produce a different exact size.
Listen at the beginning, middle and end, verify duration and inspect title and artist metadata. Converting a low-quality recording to a higher bitrate does not restore lost detail. Export only material you are entitled to use.
References support the identified formula, unit or jurisdiction. They do not imply endorsement of this site. Check the original document for current conditions and exceptions.
English edition: 16 September 2026.