/convert/km-to-au/ Convert km to astronomical units instantly with a reference conversion table. article km to astronomical units Converter — 247QuickTools
📏 Length

km to astronomical units Converter

Convert km to astronomical units instantly with a reference conversion table.

Quick answer: To convert km to astronomical units, multiply by 6.6846e-09. For example, 1 km = 6.6846e-09 astronomical units. Use the calculator below for any value.
km to astronomical units
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Common conversions
km astronomical units
Formula:

How to convert km to astronomical units

1

Enter your value

Type the number of km you want to convert into the left box. The result in astronomical units appears instantly in the right box. You can also type into the right box to convert in the other direction.

2

Use the swap button

Click the ⇄ Swap button to reverse the conversion — astronomical units to km. Your current value carries across so you don't have to re-enter anything.

3

About km and astronomical units

km and astronomical units are common length measurements.

📊 Common conversions at a glance
km astronomical units
1 6.685e-09
1000 6.685e-06
149597871 1
1000000000.0 6.685
1000000000000.0 6685
1000000000000000.0 6.685e+06
Reviewed for 2026. km ↔ astronomical units conversion factor verified against published reference data. Built by a UK-based qualified primary teacher and FA Level 2 coach as part of 247QuickTools' free utility-tools project.

Frequently asked questions

How do I convert km to astronomical units?

To convert km to astronomical units, multiply by 6.6846e-09. Or use the calculator above for instant results.

How many astronomical units are in 1 km?

1 km equals 6.6846e-09 astronomical units.

Is the km to astronomical units converter free?

Yes, the km to astronomical units converter is completely free with no sign-up required, no downloads, and it works offline once the page has loaded.