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About this tool
Convert kilometers to astronomical units instantly. Free, bidirectional, and fully in-browser.
1 kilometer equals 6.684587e-9 astronomical units — enter any kilometer value to convert it to astronomical units instantly. This Kilometer to Astronomical unit converter is a client-side tool: it applies a single multiplication (AU = km × 6.684587e-9) in your browser, updates the moment you type, and works in both directions — edit either field, or press swap, to convert astronomical units back to kilometers. A reference table lists common kilometer values already converted, and nothing you enter is sent to a server.
Open Kilometer to Astronomical unit Converter on AltFTool — it loads instantly in your browser.
Type the value you want to convert into the Kilometer field.
Read the equivalent in astronomical units in the result field, and copy it if needed.
Use the decimal-places slider for more or less precision, or press swap to convert astronomical units to kilometers.
The result updates as you type, and the swap button flips the conversion to astronomical unit → kilometer without reloading.
The conversion uses the precise factor (AU = km × 6.684587e-9), so the number matches a manual calculation to the decimal places you choose.
A slider sets 0–10 decimal places, and very small or very large results switch to scientific notation instead of rounding to zero.
Everything runs locally in your browser — no upload, no account, no limit on conversions.
One kilometer is 6.684587e-9 astronomical units. Multiply the kilometer value by 6.684587e-9 to convert. For example, 10 km = 6.684587e-8 AU.
AU = km × 6.684587e-9. This tool applies it automatically and shows a worked example: 10 km = 6.684587e-8 AU.
Yes. Press the swap button, or type into the astronomical unit field, and the tool converts astronomical units to kilometers using the inverse of the same relationship.
It uses the standard distance and length definition (AU = km × 6.684587e-9), not a rounded approximation, so results are exact to the number of decimal places you select.
Yes. The converter is a browser-side script with no network calls: your values are never uploaded, and once the page has loaded it keeps working without a connection.
Add the Kilometer to Astronomical unit Converter widget to your blog or website — free, responsive, no signup. Just keep the “Widget by AltFTool” credit link visible.
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