Factors Affecting Size
A standard, single-layer, recordable DVD has 4.7 GB of storage space–enough for up to 2 hours (120 minutes) of video at DVD quality. Since the DVD’s invention in 1995, however, manufacturers have developed formats that allow for significantly greater storage capacity. The size of data that DVDs can hold is governed mainly by the number of sides (one or two) and layers (one or two). As you might expect, double-layer (sometimes called dual-layer) and double-sided DVDs hold more than standard single-sided, single-layer DVDs. Many DVD burners for computers now burn double-sided and double-layer DVDs.
DVD Formats
DVDs are available in various formats, each of which supports various capacities. A few of the most common include:
DVD+R and DVD-R: Can be recorded on only onceDVD+R/RW and DVD-R/RW: Can be written to, erased, and rewritten many timesDVD+R DL, DVD-R DL: Has two layers; writing/rewriting are a bit slower than other formats
Common DVD Sizes
The numbers in each format refer, roughly, to capacity in gigabytes. Actual capacity is less because technical parameters changed since the nomenclature was designated. Still, the number is a valid way to approximate how much data the DVD will hold when you’re deciding which to purchase.
DVD-5: Holds 4.7GB; single-sided, single-layer; supported by the DVD+R/RW and DVD-R/RW formatsDVD-9: Holds 8.5GB; single-sided double-layer; supported by the DVD+R and DVD-R formats; officially known as DVD-R DL and DVD+R DLDVD-10: Holds 8.75GB; double-sided single layer; supported by the DVD+R/RW and DVD-R/RW formatsDVD-18: Holds 15.9GB; double-sided double-layer; supported by the DVD+R format
Check the specifications of your DVD burner to be sure of the format you need.
DVDs Compared to Similar Media
DVDs definitely have their uses but there are also other kinds of discs you could use to store files, whether they’re software programs, pictures, videos, MP3s, etc. In some cases, you might need a disc that can hold more or less data. For example, if you need more storage space because your DVD isn’t enough, you might grab a single-layer Blu-ray Disc that can hold 25GB. There are even write-once BDXL formatted discs that can hold upwards of 100-128GB of data. However, there’s also the opposite–CDs that are good for storing less than what a DVD is capable of holding. If you only need less than one gigabyte of storage, you might be better off sticking with a CD-R or CD-RW that maxes out at 700MB. Generally, smaller capacity discs are the least expensive discs you can buy. They’re also more widely acceptable in disc drives. For instance, your average 700MB CD-R can be used in basically any modern computer or DVD player, and the same goes for most DVDs. However, a Blu-ray Disc is only usable if the device includes Blu-ray support.
