MP3 bitrate explained: 128 vs 192 vs 320 kbps
Bitrate is how much data an MP3 uses per second of sound, measured in kilobits per second (kbps). Higher bitrates keep more detail and make bigger files. Sound Trimmer offers 128, 192 and 320 kbps for MP3, or uncompressed WAV.
File size at each setting
MP3 size depends only on bitrate and length, so it is easy to predict. WAV size depends on the sample rate and the number of channels.
| Format | Per minute | 5 minutes |
|---|---|---|
| MP3 128 kbps | about 0.96 MB | about 4.8 MB |
| MP3 192 kbps | about 1.44 MB | about 7.2 MB |
| MP3 320 kbps | about 2.4 MB | about 12 MB |
| WAV 16-bit, 44.1 kHz stereo | about 10.6 MB | about 53 MB |
| WAV 16-bit, 44.1 kHz mono | about 5.3 MB | about 26 MB |
Which bitrate to choose
- 128 kbps: fine for speech, voice memos, lectures and notifications. Music can lose some sparkle in cymbals and reverb.
- 192 kbps: a good default for music, ringtones and podcasts. Most people cannot tell it from higher settings on phones and laptop speakers.
- 320 kbps: the highest MP3 setting. Use it for music you will listen to on good headphones, or when the source was already a high-bitrate file.
- WAV: no MP3 compression at all. Choose it when you will edit the file again, or when another program will encode it later.
Higher bitrate cannot add quality back
Exporting a 128 kbps source at 320 kbps makes a bigger file, not a better one. The detail removed by the first encoding is gone. As a rule, export at the same bitrate as the source or higher, and avoid repeated MP3 round trips. If you are making several edits, keep WAV between steps and save MP3 once at the end.
About WAV exports
Sound Trimmer's WAV downloads are standard 16-bit PCM at the sample rate your browser decoded, usually 44.1 or 48 kHz. That is the same format as CD audio and opens in virtually every player and editor.
MP3 padding
MP3 encoders add a tiny amount of silence, usually a few hundredths of a second, at the start and end of a file. It does not matter for most uses. For a seamless loop or a clip that must line up exactly with video, use WAV.
Reviewed October 2026 · How we write our guides · Suggest a correction