Reading the conversion rule in Astronomical Units to Kilometers
Start with the astronomical units amount and apply the defined astronomical units to kilometers rule. Multiply astronomical units by 149597870.699999988079 to obtain kilometers.
Multiply astronomical units by 149597870.699999988079 to obtain kilometers.
A reverse calculation uses kilometers as the source: Divide kilometers by 149597870.699999988079 to return to astronomical units.
When kilometers is not the required destination, open the length converter from this astronomical units to kilometers page.
When this pair of units is useful for Astronomical Units to Kilometers
A stated amount in astronomical units may need to be reported in kilometers for planetary distances, orbit descriptions, astronomy tables, and solar-system models.
Nothing physical changes during astronomical units to kilometers; the numerical value changes because AU and km divide the length scale differently.
Definitions behind AU and km
The source symbol AU denotes astronomical units; the destination symbol km denotes kilometers. Their fixed link in astronomical units to kilometers is 149597870.699999988079.
A linear distance keeps one length dimension; area and volume would require different factors. On this page, astronomical units never silently changes standard before becoming kilometers. Labeling both values protects the astronomical units to kilometers record from being read in the wrong unit later.
Example from the input box: AU to km
For the displayed case, 1 AU corresponds to 149,597,870.7 km. The arithmetic line is 1 × 149597870.699999988079 = 149,597,870.7.
Half, baseline, and larger inputs give three checkpoints for judging the scale of kilometers.
0.5 AU74,798,935.35 km
1 AU149,597,870.7 km
2.5 AU373,994,676.75 km
Using kilometers in context
A document for planetary distances, orbit descriptions, astronomy tables, and solar-system models may place astronomical units and kilometers side by side. State which column uses AU and which uses km before comparing them.
If the converted kilometers value controls a purchase, setting, or limit, confirm the source definition and rounding rule. That context is more important than presenting the maximum possible decimals.
The unit ratio for Astronomical Units to Kilometers
The forward unit ratio is 149,597,870.7 km per AU. The reciprocal scale for astronomical units to kilometers is 0 AU per km.
Multiplying by a ratio whose denominator is AU leaves km on the result. That cancellation is a useful handwritten check.
Checking in reverse for Astronomical Units to Kilometers
Predict whether the km number should be larger or smaller than the AU number by inspecting the factor 149597870.699999988079.
Then apply the inverse rule to the displayed kilometers amount and look for the starting astronomical units value.
Carrying the km result forward
A downstream calculation should receive the full kilometers result, not a prematurely rounded display. Preserve astronomical units in AU so the astronomical units to kilometers step remains reproducible.
Rounding the converted value for kilometers
A working value in km may need more decimals than a printed label. Keep them through the purpose of the astronomical units to kilometers result is known.
If astronomical units was estimated, report kilometers as an estimate too. A long km display does not make the source more exact.
Questions about astronomical units to kilometers
What is the formula for astronomical units to kilometers?
Multiply astronomical units by 149597870.699999988079 to obtain kilometers. Divide kilometers by 149597870.699999988079 to return to astronomical units.
How can I check the kilometers result?
Apply the reverse relationship to the kilometers result. It should return the original astronomical units value within the displayed rounding.
Does zero AU equal zero km?
Yes. Zero AU maps to zero km because astronomical units to kilometers has no zero-point offset.
How should kilometers be rounded after astronomical units to kilometers?
Carry guard digits in kilometers while it is still a working value. Present km with no more resolution than the original AU measurement warrants.