Why make a file ten times bigger?
Because the tool on the other end demands it. Many audio editors, hardware samplers, phone systems and broadcast workflows accept only WAV — uncompressed PCM they can cut, loop and process sample-accurately without decoding on the fly. Converting once here beats fighting an import dialog.
There is a quieter benefit too: once audio is WAV, editing and re-saving costs nothing. Re-saving an MP3 as MP3 re-compresses it every time, and that generational loss stacks up.
What WAV does not do
It does not restore quality. The detail the original MP3 encoder discarded is gone; WAV faithfully stores exactly what the MP3 contained, no more. Bigger file, identical sound — that is the honest deal.
Frequently asked questions
Will WAV sound better than my MP3?
No — it will sound identical. WAV stores the decoded audio without further loss, but cannot invent the detail the MP3 encoder threw away.
Why does my editor insist on WAV?
Uncompressed PCM is trivial to seek, cut and process precisely. Some editors decode MP3 behind the scenes; many hardware samplers and phone systems simply don't.
How big will the file be?
Around 10 MB per minute of stereo audio — roughly ten times the MP3. That's the nature of uncompressed audio, not a bug.