# What is volume in "km"^3?

In $1$ $k {m}^{3}$? Well ${10}^{9}$ ${m}^{3}$.
One cubic kilometre is equivalent to one thousand million cubic metres, i.e. $1 \cdot k {m}^{3}$ $=$ ${\left[1 \times {10}^{3}\right]}^{3} \cdot {m}^{3}$ $=$ ${10}^{9} \cdot {m}^{3}$.