18 Astronomical Unit to Kilometer
Quick answer
18 Astronomical Unit (AU) equals
2,692,761,672.6 km
To convert 18 Astronomical Units to Kilometers, multiply by 149,597,870.7. Therefore, 18 Astronomical Unit (AU) equals 2,692,761,672.6 Kilometer (km).
Formula: km = AU × 149,597,870.7. Calculation: 18 × 149,597,870.7 = 2,692,761,672.6 km.
Convert Astronomical Unit (AU) to Kilometer (km) online with our free unit converter. In length, 1 AU = 149,597,870.7 km. Explore step-by-step conversion steps, mathematical formulas, and quick conversion reference tables below.
Worked example: converting Astronomical Unit to Kilometer
- Step 1 — start with the formula. km = AU × 149,597,870.7
- Step 2 — substitute your figure. 18 AU × 149,597,870.7
- Step 3 — read the result. 18 AU = 2,692,761,672.6 km
- Step 4 — check it in reverse. AU = km × 6.684587e-9 returns Invalid AU, which matches the figure you started with.
Length Converter
31 units available
18 AU = 2,692,761,672.6 km
Formula:
km = AU × 149,597,870.7With your value: 18 AU = 2,692,761,672.6 km
How big is that?
Everyday references on a logarithmic scale, all expressed in astronomical unit so you can sanity-check the result.
Other Astronomical Unit to Kilometer conversions
Astronomical Unit to Kilometer Conversion Table
| Astronomical Unit (AU) | Kilometer (km) |
|---|---|
| 0.5 | 74,798,935.35 |
| 1 | 149,597,870.7 |
| 2 | 299,195,741.4 |
| 5 | 747,989,353.5 |
| 10 | 1,495,978,707 |
| 15 | 2,243,968,060.5 |
| 20 | 2,991,957,414 |
| 25 | 3,739,946,767.5 |
| 50 | 7,479,893,535 |
| 100 | 14,959,787,070 |
| 250 | 37,399,467,675 |
| 500 | 74,798,935,350 |
| 1000 | 149,597,870,700 |
Kilometer to Astronomical Unit Conversion Table
| Kilometer (km) | Astronomical Unit (AU) |
|---|---|
| 0.5 | 3.342294e-9 |
| 1 | 6.684587e-9 |
| 2 | 1.336917e-8 |
| 5 | 3.342294e-8 |
| 10 | 6.684587e-8 |
| 15 | 1.002688e-7 |
| 20 | 1.336917e-7 |
| 25 | 1.671147e-7 |
| 50 | 3.342294e-7 |
| 100 | 6.684587e-7 |
| 250 | 1.671147e-6 |
| 500 | 3.342294e-6 |
| 1000 | 6.684587e-6 |
Where these values come from
Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.
Astronomical Unit (AU)
Length
The astronomical unit is exactly 149 597 870 700 m (IAU Resolution B2, 2012).
Source: IAU Resolution B2 (2012) — definition of the astronomical unit; IAU B2 (2015) nominal values
International Astronomical Union · Reviewed 2026-07-01
Kilometer (km)
Length
Traceable to the metre, defined by fixing the speed of light in vacuum at 299 792 458 m/s. Imperial lengths derive from the 1959 international yard (0.9144 m exactly).
Source: BIPM, The International System of Units (SI), 9th edition, 2019 (updated 2024)
Bureau International des Poids et Mesures · Reviewed 2026-07-01
How to Convert Astronomical Unit to Kilometer
To convert from Astronomical Unit (AU) to Kilometer (km), multiply the value by 149,597,870.7.
Formula: km = AU × 149,597,870.7
Reverse: AU = km × 6.684587e-9
Step-by-Step Example
- Start with your value in Astronomical Unit. For example: 5 AU
- Multiply by the conversion factor: 5 x 149,597,870.7
- The result is: 747,989,353.5 km
Astronomical Unit and Kilometer Relationship
This conversion bridges the Astronomical and Metric (SI) measurement systems, commonly required when translating scientific data, international engineering specifications, or trade standards. Since 1 Astronomical Unit equals approximately 1.496e+8 Kilometers, the Astronomical Unit represents a larger unit interval than the Kilometer. Understanding the relationship between Astronomical Unit and Kilometer is essential for accurate calculations in physics, engineering, commerce, and daily applications.
About Astronomical Unit
The astronomical unit (AU) is defined as exactly 149,597,870,700 metres, close to the mean Earth–Sun distance. It is the natural yardstick for the Solar System.
Common uses of Astronomical Unit: planetary science, orbital mechanics, astronomy.
About Kilometer
The kilometer equals 1,000 meters and is the standard unit for measuring distances between geographical locations in most countries.
Fun Fact: The circumference of Earth is approximately 40,075 km.
Common uses of Kilometer: road distances, geography, running.
Frequently Asked Questions
- What is 18 Astronomical Unit in Kilometer?
- 18 Astronomical Unit equals 2,692,761,672.6 Kilometer.
- How many Kilometers are in 1 Astronomical Unit?
- There are exactly 149,597,870.7 Kilometers in 1 Astronomical Unit. This means the conversion factor from Astronomical Unit to Kilometer is 149,597,870.7.
- What is the formula to convert Astronomical Unit to Kilometer?
- The formula to convert Astronomical Unit to Kilometer is: km = AU × 149,597,870.7. For example, to convert 10 Astronomical Units to Kilometers, you would multiply 10 by 149,597,870.7.
- What is a Astronomical Unit?
- The astronomical unit (AU) is defined as exactly 149,597,870,700 metres, close to the mean Earth–Sun distance. It is the natural yardstick for the Solar System.
- What is a Kilometer?
- The kilometer equals 1,000 meters and is the standard unit for measuring distances between geographical locations in most countries.
- What are the common uses of Astronomical Unit?
- The Astronomical Unit is commonly used in planetary science, orbital mechanics, astronomy.
Related Length Conversions
Cite this page
UnitConvertLab. (2026). 18 Astronomical Unit to Kilometer. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/18-astronomical_unit-to-kilometer