dvd sizes

The basic types of DVD (12 cm diameter, single-sided or homogeneous double-sided) are referred to by a rough approximation of their capacity in gigabytes. In draft versions of the specification, DVD-5 indeed held five gigabytes, but some parameters were changed later on as explained above, so the capacity decreased. Other formats, those with 8 cm diameter and hybrid variants, acquired similar numeric names with even larger deviation.

The 12 cm type is a standard DVD, and the 8 cm variety is known as a MiniDVD. These are the same sizes as a standard CD and a mini-CD, respectively. The capacity by surface (MiB/cm²) varies from 6.92 MiB/cm² in the DVD-1 to 18.0 MiB/cm² in the DVD-18.

As with hard disk drives, in the DVD realm, gigabyte and the symbol GB are usually used in the SI sense (i.e., 10⁹, or 1,000,000,000 bytes). For distinction, a gigabyte is normally used in the binary sense (i.e., 1024³ (2³⁰), or 1,073,741,824 bytes).

Each DVD sector contains 2,418 bytes of data, 2,048 bytes of which are user data. There is a small difference in storage space between + and - (hyphen) formats:

Capacity and nomenclature
SS = single-sided, DS = double-sided, SL = single-layer, DL = dual-layer

Designation		Sides	Layers (total)	Diameter (cm)	Capacity
					(GB)
DVD-1	SS SL	1	1	8	1.36
DVD-2	SS DL	1	2	8	2.47
DVD-3	DS SL	2	2	8	2.72
DVD-4	DS DL	2	4	8	4.95
DVD-5	SS SL	1	1	12	4.37
DVD-9	SS DL	1	2	12	7.95
DVD-10	DS SL	2	2	12	8.75
DVD-14	DS SL+DL	2	3	12	12.33
DVD-18	DS DL	2	4	12	15.90

Capacity and nomenclature of (re)writable discs

Designation		Sides	Layers (total)	Diameter (cm)	Capacity
					(GB)
DVD-R	SS SL (1.0)	1	1	12	3.68
DVD-R	SS SL (2.0)	1	1	12	4.37
DVD-RW	SS SL	1	1	12	4.37
DVD+R	SS SL	1	1	12	4.37
DVD+RW	SS SL	1	1	12	4.37
DVD-R	SS DL	1	2	12	7.96
DVD-RW	SS DL	1	2	12	7.96
DVD+R	SS DL	1	2	12	7.96
DVD+RW	SS DL	1	2	12	7.96
DVD-RAM	SS SL	1	1	8	1.36*
DVD-RAM	DS SL	2	1	8	2.47*
DVD-RAM	SS SL (1.0)	1	1	12	2.40
DVD-RAM	SS SL (2.0)	1	1	12	4.37
DVD-RAM	DS SL (1.0)	2	1	12	4.80
DVD-RAM	DS SL (2.0)	2	1	12	8.75*

DVD regions

DVD region codes are a digital rights management technique designed to allow film distributors to control aspects of a release, including content, release date, and price, according to the region.

This is achieved by way of region-locked DVD players, which will play back only DVDs encoded to their region (plus those without any region code). The commercial DVD player specification requires that a player designed to be sold in a given place play only discs encoded for that region (plus those without any region code).

Regions - 

code	Area
0	Informal term meaning "worldwide". Region 0 is not an official setting; discs that bear the region 0 symbol either have no flag set or have regions 1–6 flags set. Region 0 is commonly referred to as "Region Free", especially when talking about DVD and Blu-ray Disc players.
1	United States, Canada, Bermuda, Caribbean, U.S. territories
2	Europe, Middle East, Egypt, Japan, South Africa, Swaziland, Lesotho, Greenland, French Overseas departments and territories
3	Southeast Asia, South Korea, Taiwan, Hong Kong, Macau
4	South America, Central America, Mexico, New Zealand, Australia, Papua New Guinea and much of Oceania
5	Bangladesh, India, Nepal, Afghanistan, Sri Lanka, Ukraine, Belarus, Russia, Kazakhstan, Pakistan, Africa (except Egypt, South Africa, Swaziland, Lesotho), Central Asia, Mongolia,North Korea
6	China
7	Reserved for future use, MPAA-related DVDs and "media copies" of pre-releases in Asia
8	International venues such as aircraft, cruise ships, spacecraft, etc.
ALL	Region ALL discs have all eight flags set, allowing the disc to be played in any location, on any player.