Kilometer to Astronomical Unit Conversion Calculator: Free Online Tool
Convert kilometers to astronomical units with our free online length converter.
Kilometer to Astronomical Unit Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Kilometer).
- The converted value in Astronomical Unit will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Length category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Kilometer to Astronomical Unit
Converting Kilometer to Astronomical Unit involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Kilometer = 6.6845e-9 astronomical unitsExample Calculation:
Convert 10 kilometers: 10 × 6.6845e-9 = 6.6845e-8 astronomical units
Note: Conversion factors can sometimes be rounded for display purposes. For precise calculations, always use the full factor or rely on the calculator above.
What is a Kilometer and a Astronomical Unit?
The kilometer is a unit of length in the metric system equal to one thousand meters (1,000 m). It is commonly used to measure geographic distances.
An astronomical unit is a unit of length roughly equal to the average distance between Earth and the Sun. It is defined as exactly 149,597,870,700 meters.
Note: The Kilometer is part of the metric (SI) system, primarily used globally in science and trade. The Astronomical Unit belongs to the imperial/US customary system.
History of the Kilometer and Astronomical Unit
Derived directly from the meter, the kilometer was established as part of the metric system in the late 18th century to provide a larger, convenient unit for measuring longer distances, such as those between cities or the lengths of roads.
Historically used to measure distances within the Solar System, its value was refined over centuries through astronomical observations. The exact definition was adopted by the IAU in 2012.
Common Uses for kilometers and astronomical units
Explore the typical applications for both Kilometer (metric) and Astronomical Unit (imperial/US) to understand their common contexts.
Common Uses for kilometers
- Geography & Travel: Measuring distances between geographical locations (cities, countries).
- Transportation: Road signs indicating distances and speed limits (km/h) in metric countries.
- Mapping: Measuring the length of roads, rivers, or coastlines.
- Athletics: Athletic events like long-distance running (e.g., 5k, 10k, marathon).
- Logistics: Calculating travel times and fuel efficiency.
Common Uses for astronomical units
- Measuring distances within the Solar System (e.g., planet orbits)
- Expressing distances to near-Earth objects
Frequently Asked Questions
Questions About Kilometer (km)
How many meters are in a kilometer?
There are exactly 1,000 meters (m) in 1 kilometer (km).
What does 'kilo' mean in kilometer?
The prefix 'kilo' denotes one thousand (1,000).
Is a kilometer longer or shorter than a mile?
A kilometer is shorter than a mile. One mile is approximately 1.609 kilometers.
About Astronomical Unit (AU)
Why use Astronomical Units instead of kilometers or miles?
Astronomical Units (AU) provide a more convenient scale for the vast distances within our solar system. Expressing interplanetary distances in km or miles results in extremely large and unwieldy numbers.
How many kilometers/miles is 1 AU?
1 Astronomical Unit (AU) is approximately 149.6 million kilometers or 93 million miles.
How long does it take light to travel 1 AU?
It takes sunlight approximately 8 minutes and 20 seconds to travel the distance of one Astronomical Unit from the Sun to the Earth.
Conversion Table: Kilometer to Astronomical Unit
| Kilometer (km) | Astronomical Unit (AU) |
|---|---|
| 1 | 0 |
| 5 | 0 |
| 10 | 0 |
| 25 | 0 |
| 50 | 0 |
| 100 | 0 |
| 500 | 0 |
| 1,000 | 0 |