What is the storage capacity of a DVD multilayer?

The most common DVD type is DVD-5 (1 side, 1 layer) having 4.7GB of storage. Double-sided DVDs are rarely used.

DVD-5 4.70GB Single sided, Single layer

DVD-9 8.54GB Single sided, Dual layer

DVD-10 9.40GB Double sided, Single layers

DVD-14 13.24GB Double sided, One side single layer, one side dual layer

DVD-18 17.08GB Double sided, Dual layer