Make a delivery copy
A WAV is useful as a working master, but a receiving form or player may need MP3. This conversion encodes a new lossy file. Keep the WAV so that later exports can start from the original rather than a previously compressed copy.
Read the source before choosing
The preview accepts supported mono/stereo integer16/24 or float32 WAV for MP3 encoding. It retains the admitted sample rate and channels. A 32-bit integer WAV is refused for this path rather than silently reduced. Low source rates can restrict the available MP3 bitrate.
Settings and a size example
The qualified encoder is LAME CBR, algorithm quality 0, up to 320 kbps where the source rate permits. Three minutes at 320 kbps has an estimated 7.2 MB audio payload before headers and tags. The download's actual byte count is the figure to check.
Check the saved MP3
Play the beginning, ending and an important passage in the receiving app. Confirm the duration and review metadata warnings. Read the bitrate guide and the generation-loss explanation before discarding a master.