[shalmanese]

is a km3 1000 m3 or 1,000,000,000 m3?

[OptionOfT]

to go from km to m you multiply by 1,000.

to go from km^2 to m^2 you multiply by 1,000^2.

to go from km^3 to m^3 you multiply by 1,000^3.

So 1km^3 is 1,000,000,000m^3