Example:
15 DVD (1 layer, 2 sides) = 1.211181e+12 b
1 DVD (1 layer, 2 sides) = 8.074539e+10 b | 1 b = 1.238461e-11 DVD (1 layer, 2 sides)
Conversion Steps:
15 × (8.074539e+10 / 1) = 1.211181e+12