Exported WAV files larger than imported WAV files

I wanted to use Audacity to ‘trim’ the end of a 3-hour DJ mix.

The original WAV file is 1.77GB. Upon editing the file to fade out at the end, and then exporting it as a WAV file, the resultant WAV file is 3.57GBs!

Why does this happen and how do I prevent it? Ideally, the exported WAV file should be the same size as the original imported file if not slightly smaller due to loss of data in encoding. When I export the edited mix as an MP3, it amounts to a 411MB file. This makes sense given how much is lost upon encoding to MP3, but why a BIGGER WAV file when exporting as a WAV file?? Surely that means there’s a whole bunch of ‘noise’ as data in the exported WAV file. I thought WAV files were not subject to compression and therefore there would be no reason the exported file is larger, unless more ‘noise’ data has been added somehow.

What am I missing? What settings should I use to enable the exported WAV file to be the same or similar size to the original WAV file?

Thanks in advance…

What does this page say the format is for the original file? https://mediaarea.net/MediaInfoOnline
(Please post all of the details)

Curiously, 1.77 by two is 3.54.

Is there a chance that the file is being converted from mono to stereo?

or from 8-bit to 16-bit, or from 16-bit to 32-bit or was the original file not actually WAV format?
The default format when Exporting from Audacity as WAV is 16-bit WAV (mono or stereo depending on whether the project is mono or stereo).

If you know there are 8-bits in a byte (and if you know the format details and playing time) you can calculate the file size for uncompressed files.

For example, 16-bit stereo is 2 bytes per sample x 2-channels so that’s 4 bytes per (stereo) sample. At 44.1kHz, that’s 176,400 bytes per second.

For compressed files you need to know the (average) bit rate. The bit rate is normally given in kbps = kilo_bits_ per second so you can divide by 8 to get kilo_bytes_ per second.

(If there is embedded artwork, of course that adds to file size.)