WAV to MP3 Converter

WAV files are uncompressed: about 10 MB for every minute of CD-quality stereo. MP3 shrinks that to about 1.4 MB per minute at 192 kbps while sounding the same to most listeners, which makes it the format to use for email, phones and upload limits. The conversion happens in your browser, so recordings never leave your device.

How to use this tool

1. Choose one or more WAV files.
2. Pick a bitrate: 192 kbps for music, 128 kbps for speech, 320 kbps for the best quality.
3. Switch to mono for voice recordings if you want an even smaller file.
4. Press Calculate and download the MP3s (several at once as a ZIP).

Formula

WAV size = sample rate × channels × bits ÷ 8 × seconds · MP3 size ≈ kbps × 1000 ÷ 8 × seconds

The sample rate is read from the WAV header and kept when MP3 supports it (8–48 kHz); 88.2, 96 or 192 kHz recordings are converted to 48 kHz. Low sample rates limit the bitrate: at 8–12 kHz MP3 allows at most 64 kbps, at 16–24 kHz 160 kbps. Unusual WAV codecs that the browser cannot decode are converted with the ffmpeg engine (about 30 MB, downloaded once).

Example

A 5-minute stereo WAV at 44.1 kHz/16-bit is 44,100 × 2 × 2 × 300 ≈ 52.9 MB. At 192 kbps the MP3 is 192,000 ÷ 8 × 300 = 7.2 MB, about 86% smaller.