What is the maximum capacity of a DVD-r?

DVD-R 2,298,496 sectors 4.384 GB

Have seen slightly contradictory info for Dual Layer discs:

DVD-9 SS DL
8.54 GB
7.95 GiB

DVD+R DL 8,547,991,552 Byte =
8.55 GB
7.961 GiB

Don't try to fill to absolute maximum capacity, though, you'd be asking for errors.

When writing, I use 4480MB as the maximum, it has worked fine.