Cubic Kilometre (km³)
The cubic kilometre is used for global water stocks and very large lakes and rivers; it equals one BCM.
Symbol: km³ (ASCII: km3)
Quantity: volume of stored or released water (reservoirs, river flows, allocations)
SI relation: 1 km³ = 1000 MCM (exact)
Derivation: 1 km³ = 10⁹ m³ = 1 BCM.
Exact: yes, by definition
Same quantity as billion cubic metres (BCM) : the factor between them is exactly 1.
Typical uses
- Global water budgets
- Large lake and glacier volumes
Convert cubic kilometres to other units
| Conversion | 1 km³ equals | Reverse |
|---|---|---|
| cubic kilometre to MCM | 1000 MCM | MCM to cubic kilometre |
| cubic kilometre to BCM | 1 BCM | BCM to cubic kilometre |
| cubic kilometre to TMC | 35.31466672 TMC | TMC to cubic kilometre |
| cubic kilometre to acre-foot | 810713.1938 acre-ft | acre-foot to cubic kilometre |
| cubic kilometre to cubic metre | 1000000000 m³ | cubic metre to cubic kilometre |
| cubic kilometre to Mcft | 35314.66672 Mcft | Mcft to cubic kilometre |
| cubic kilometre to MAF | 0.8107131938 MAF | MAF to cubic kilometre |
| cubic kilometre to hectare-metre | 100000 ha·m | hectare-metre to cubic kilometre |
| cubic kilometre to megalitre | 1000000 ML | megalitre to cubic kilometre |
| cubic kilometre to gigalitre | 1000 GL | gigalitre to cubic kilometre |
Open the Water Volume Converter (TMC, MCM, Acre-foot) to convert any value between all units.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4 (derived units) and Table 8 (non-SI units accepted for use with the SI).
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Cubic Kilometre (km³). Retrieved October 29, 2026, from https://scientificconverters.com/units/cubic-kilometer/
IEEE
Scientific Converters, "Cubic Kilometre (km³)," scientificconverters.com. Accessed: Oct. 29, 2026. [Online]. Available: https://scientificconverters.com/units/cubic-kilometer/