Convert Cubic Kilometres to BCM (km3 to BCM)
1 cubic kilometre (km³) = 1 billion cubic metres (BCM). 1 BCM = 1 km³. Example: 15 km³ = 15 × 1 = 15 BCM.
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1 km³ = 1 BCM
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk cubic kilometre to BCM converter to paste a column from Excel.
How to Convert Cubic Kilometre to BCM
- 1 km³ = 1 BCM
- 1 BCM = 1 km³
- Example: convert 15 km³ to BCM: 15 km³ = 15 × 1 BCM = 15 BCM
Formula
BCM = km³ × 1
Derivation from SI units:
- 1 km³ = 10⁹ m³ = 1 BCM.
- 1 BCM = 10⁹ m³ = 1000 MCM = 1 km³.
- 1 km³ = 1000 MCM ÷ 1000 MCM per BCM = 1 BCM
Both units are defined exactly, so the factor is exact. Cubic Kilometre definition: cubic kilometre; BCM definition: billion cubic metres.
Worked examples
- A reading of 10 km³ converts to 10 BCM.
10 km³ × 1 = 10 BCM - A value of 500 km³ is 500 BCM.
500 km³ × 1 = 500 BCM
Cubic Kilometre to BCM conversion table
| Cubic Kilometres (km³) | BCM |
|---|---|
| 0.1 km³ | 0.1 BCM |
| 1 km³ | 1 BCM |
| 5 km³ | 5 BCM |
| 10 km³ | 10 BCM |
| 50 km³ | 50 BCM |
| 100 km³ | 100 BCM |
| 500 km³ | 500 BCM |
| 1000 km³ | 1000 BCM |
| 4000 km³ | 4000 BCM |
| 10000 km³ | 10000 BCM |
Where it's used
Cubic Kilometres are used for global water budgets, while billion cubic metres appear in national water resources assessments. Both measure volume of stored or released water (reservoirs, river flows, allocations), so the conversion is a fixed factor.
Cubic Kilometre to other water volume units
| Conversion | 1 km³ equals |
|---|---|
| cubic kilometre to BCM | 1 BCM |
| cubic kilometre to MCM | 1000 MCM |
| cubic kilometre to TMC | 35.31466672 TMC |
| cubic kilometre to acre-foot | 810713.1938 acre-ft |
| cubic kilometre to cubic metre | 1000000000 m³ |
| cubic kilometre to Mcft | 35314.66672 Mcft |
| cubic kilometre to MAF | 0.8107131938 MAF |
| cubic kilometre to hectare-metre | 100000 ha·m |
Show 2 more units
| cubic kilometre to megalitre | 1000000 ML |
|---|---|
| cubic kilometre to gigalitre | 1000 GL |
Frequently asked questions
How many billion cubic metres are in 1 cubic kilometre?
1 km³ = 1 BCM.
How do I convert cubic kilometres to billion cubic metres?
Multiply the value in km³ by 1. For example, 15 km³ × 1 = 15 BCM.
Is the km³ to BCM conversion exact?
Yes. Both units are defined exactly, and 1 km³ is exactly 1 BCM.
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). Convert Cubic Kilometres to BCM (km3 to BCM). Retrieved October 29, 2026, from https://scientificconverters.com/water-volume/cubic-kilometers-to-bcm/
IEEE
Scientific Converters, "Convert Cubic Kilometres to BCM (km3 to BCM)," scientificconverters.com. Accessed: Oct. 29, 2026. [Online]. Available: https://scientificconverters.com/water-volume/cubic-kilometers-to-bcm/