kubikkilometer

A kubikkilometer (symbol: km³) is a unit of volume in the metric system corresponding to the volume of a cube with sides of one kilometer. It is a derived SI unit, combining the SI prefix kilo- (1000) with the base unit cubic meter. One kubikkilometer equals 1,000,000,000 cubic meters (1 × 10^9 m³) or 1,000,000,000,000 liters (1 × 10^12 L).

The kubikkilometer is used for measuring very large volumes that are impractical to express in cubic meters or liters, for example the volumes of oceans, large lakes, reservoirs, glaciers, and significant earth-moving or geological deposits. In hydrology and glaciology it helps convey totals of water storage and ice mass on regional to global scales.

Notation varies; it is commonly written as km³ or km^3. As with other metric units, conversion to other units of volume follows directly from powers of ten, facilitating calculations in scientific and engineering contexts. The term is equivalent to the English "cubic kilometer" and is used across languages with minor orthographic adjustments.