Danube
The Danube is a major river in central and eastern Europe, flowing from Germany's Black Forest to the Black Sea.
Also known as: Danube River, River Danube
How big is it?
2,850 km long
Also 1,771 mi
Approximate main-channel length · approximate
Typical recorded range: 2,800 km to 2,900 km.
A little perspective
About the same scale as Triton.
Triton: Triton is a natural satellite of Neptune, with a retrograde orbit and a surface of frozen nitrogen.
Measurements, assumptions & sources +
Danube
The Danube is commonly described as approximately 2,850 km long from the Black Forest to the Black Sea. Headwater and channel-centreline conventions affect the total.
Encyclopaedia Britannica — Danube River
The marked approximate main-channel length is calibrated. Unmeasured illustration details are representative.
Triton
Rounded mean-radius model of Triton. The derived area and volume describe a sphere; surface terrain and flattening are omitted.
NASA JPL — Planetary satellite physical parameters
The marked mean diameter is calibrated. Unmeasured illustration details are representative.
Change your perspective
Put it next to…
Choose a suggestion to redraw the comparison, or open its page to learn what it is.
Why this measurement?
Why we use 2,850 km
For comparison, this page uses approximate main-channel length. This is labelled approximate; the central value is useful for comparison, while real values or measurement solutions can vary. The recorded range is 2,800 km to 2,900 km.
The Danube is commonly described as approximately 2,850 km long from the Black Forest to the Black Sea. Headwater and channel-centreline conventions affect the total.
The marked horizontal span follows the named feature; transparent margins and unmeasured details do not alter it. How calibrated comparisons work →
Recorded properties
Danube dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 2,850 km | 2,800 km to 2,900 km | approximate |
Around this scale
Go smaller. Go bigger.
These links use compatible length records, ordered around the selected value.
Around the same scale · SpaceTriton2,705 kmTriton is a natural satellite of Neptune, with a retrograde orbit and a surface of frozen nitrogen.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- Encyclopaedia Britannica — Danube RiverApproximately 2,850 km from the Black Forest to the Black Sea under the cited river convention.
There’s always another scale



