As its quite easy to get this, it would be cool to have it.

Currently when exporting to wave, you'll see a progressbar, how much filesize has been rendered yet, and how much time has been elapsed.

These data are necessary to calculate how much time it will take.

Since you know how much time it took to get to the current progress, you can simply calculate what time it would display if it was at 100 %.

Lets say that we have the following variables:

- FilesizeT = Total filesize of the wavefile (or otherwise what allows you to know what 100% is in the progress bar)
- FilesizeC = Current filesize (counter that increases as a byte has been written, or otherwise what allows you to know how much has been rendered already)
- TimeS = Time in seconds since the render has been started.

Lets pretend that we don't know anything else, here are some more variables calculated from the above vars.

- Progress = 100 / FilesizeT * FileSizeC // gives the current progress in percentages
- ET = (100 / Progress) * TimeS // Gives total Estimated time.
- ETL = ET - TimeS // Gives Estimated Time Left in Seconds.

I've confirmed these calculations to be working due to an Excelsheet I made. Do note that it will not be able to calculate when either of the values are 0 (like progress = 0%, or the FilesizeC or TimeS = 0.