People often mistake a 4.7 GB disc or the burning software to be defective since it can only write a maximum of 4.38 GB information into the disc. This is not a defect on the DVD or a bug on your burning software, but rather an industry inconsistency. The 4.7 "GIG" that is calculated is actually 4.7 billion bytes. However, on a computer, it takes 1024 bytes, not merely 1000, to make up a full MB.
The 4.7 GIG discs = 4.38 GB = 4489 MB (for DVD-R) and 4483 (for DVD+R)
This logic is not only applicable for DVD media. For example, an 80 GB hard disk will only be formatted to about 74.4 GB.