Nero Express 6 miscalculates compilation size, won't burn disc

I’m trying to burn three data files, each 1,566,790,656 bytes, to DVD+R. The three files, in total, amount to 4,700,371,968 bytes, which is 336 bytes short of the 4,700,372,992 byte limit allowed on single-sided/layer DVD+R media. In the compilation window, Nero lists these files as being 1,530,069 kilobytes each (which, when converted, add up to a total of 4,700,371,968 bytes - the same figure as before).

When I try to actually burn these files, as a finalized, non-multisession disc, Nero gives the following error message:

*** There is not enough space to burn this compilation onto this disc.
*** Please insert another disc that provides more space…

*** Data to be written: 4,483 MB (4,700,766,208 bytes)
*** Space available on disc: 4,482 MB (4,700,372,992 bytes)

Can someone please explain why Nero would first list the compilation as being 4,700, 371,968 bytes and then later change that figure to 4,700,766,208 bytes?

It won’t be just the files written to the disc, there’ll be a table of contents which will take some extra space.

Thanks, Tim. But how do I calculate the number of bytes the table of contents will be in a compilation beforehand, so that I can adjust the size of the files I intend to burn to make them fit on the disc?

No idea I’m afraid.