Digital Versatile Disc (DVD) Storage Capacities

The Digital Versatile Disc (DVD) is an optical disc storage format invented and developed in 1995. It offers significantly higher storage capacity than its predecessor, the Compact Disc (CD).

Standard DVD Capacities

• Single-Sided, Single-Layer (DVD-5): 4.7 GB (4.37 GiB)
• Single-Sided, Dual-Layer (DVD-9): 8.5 GB (7.92 GiB)
• Double-Sided, Single-Layer (DVD-10): 9.4 GB (8.75 GiB)
• Double-Sided, Dual-Layer (DVD-18): 17.0 GB (15.8 GiB)

DVD Layer Structure and Reading

DVDs store data in a spiral track of pits and lands. Dual-layer discs utilize two data layers that can be read by refocusing the laser. Double-sided discs require manual flipping to access the second side.

DVD Formats and Variations

Several formats exist, including DVD-ROM (read-only), DVD-R (recordable), DVD+R (recordable), DVD-RW (rewritable), and DVD+RW (rewritable). The "+" formats offer some performance improvements compared to the "-" formats, though both are widely compatible. DVD-RAM is a less common rewritable format.

Comparison to Other Optical Media

Compared to CDs, DVDs utilize a shorter wavelength laser (650 nm vs 780 nm), smaller pit size, and tighter track pitch, enabling higher data densities. Blu-ray Discs offer even greater capacities, utilizing a 405 nm laser.

Practical Considerations

Reported or marketed capacities may differ slightly from actual usable space due to formatting overhead and file system structures.