An astronomical unit is the mean Earth-Sun distance.
Astronomical units to Feet Converter — AU to ft
Convert Astronomical unit (AU) to Foot (ft) using the exact conversion factor (1 astronomical unit = 490,806,662,400 foot). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Astronomical units to Feet converter
Converter
Length Converter
Convert SI, imperial, US customary, astronomical, scientific, and historical length units.
Context values
Some unit families need one extra value for a physically accurate result.
A foot is exactly 0.3048 meters.
Result = input x 1.49597871e+11 / 0.3048.
Length uses the meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Astronomical units to Feet
Astronomical unit and Foot both measure length. Astronomical unit is typically associated with used internationally in astronomy for solar-system-scale distances., while Foot is typically associated with united States (height, construction, aviation altitude).
Formula
feet = astronomical units × 490806662402
This factor comes from each unit's defined relationship to the category's base unit: 1 astronomical unit equals 149597870700 base units, and 1 foot equals 0.3048 base units, so dividing one by the other gives the direct astronomical unit-to-foot factor of 490806662402.
Simple example
1 AU × 490806662400 = 490,806,662,400 ft
1 astronomical unit = 490,806,662,400 feet.
Real-world example
10 AU × 490806662400 = 4.908067e+12 ft
10 astronomical units = 4.908067e+12 feet.
Conversion table
| Astronomical unit (AU) | Foot (ft) |
|---|---|
| 1 AU | 490,806,662,400 ft |
| 5 AU | 2.454033e+12 ft |
| 10 AU | 4.908067e+12 ft |
| 21.0975 AU | 1.035479e+13 ft |
| 42.195 AU | 2.070959e+13 ft |
| 100 AU | 4.908067e+13 ft |
Reverse conversion: Foot to Astronomical unit
1 ft × 2.037462e-12 = 2.037462e-12 AU
1 foot = 2.037462e-12 astronomical units.
astronomical units = feet × 2.037462e-12
For a page dedicated to this direction, see Foot to Astronomical unit.
Astronomical unit vs. Foot
| Aspect | Astronomical unit | Foot |
|---|---|---|
| Family | Non-SI unit accepted for use with SI (astronomical) | US/imperial customary unit |
| Typical use | Measuring distances within the solar system (planetary orbits) | Height measurement in the US and UK |
| Where it's used | Used internationally in astronomy for solar-system-scale distances. | United States (height, construction, aviation altitude) |
Understanding the Astronomical unit
Astronomical unit (AU) measures distance. The astronomical unit is defined as exactly 149,597,870,700 meters, close to the average Earth-Sun distance. It is classified as a Non-SI unit accepted for use with SI (astronomical).
Where it's used: Used internationally in astronomy for solar-system-scale distances.
Uses of the Astronomical unit today
- Measuring distances within the solar system (planetary orbits)
- Astronomical calculations and spacecraft navigation
- Popular science communication about the solar system
History of the Astronomical unit
The astronomical unit originated from 17th-19th century attempts to measure the Earth-Sun distance, refined over time using transits of Venus and later radar and spacecraft ranging.
In 2012, the International Astronomical Union fixed the AU at exactly 149,597,870,700 meters, replacing its earlier definition (tied to gravitational calculations) with a simple fixed distance, independent of the slightly-variable actual Earth-Sun distance.
Historical origin. Astronomical unit was not the invention of a single named person; it developed through the process described above.
Understanding the Foot
Foot (ft) measures distance. The international foot is defined as exactly 0.3048 meters. It is classified as a US/imperial customary unit.
Where it's used: United States (height, construction, aviation altitude) United Kingdom (height, some construction contexts)
Uses of the Foot today
- Height measurement in the US and UK
- US construction and real estate (square footage)
- Aviation altitude worldwide (feet remain standard even in metric countries)
History of the Foot
The foot has ancient roots (Roman 'pes', various regional English feet), standardized into the modern English foot over centuries. The international foot (exactly 0.3048 m) was fixed by the 1959 International Yard and Pound Agreement, resolving small historical differences between US and UK measurements.
Historical origin. Foot was not the invention of a single named person; it developed through the process described above.
Astronomical unit — sources
- IAU Resolution B2 (2012) — Fixes the astronomical unit at exactly 149,597,870,700 meters.
Foot — sources
- NIST — International yard and pound (1959) — Fixes the modern foot at exactly 0.3048 meters.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many feet are in 1 astronomical unit?
1 astronomical unit equals 490,806,662,400 feet, using the exact defined conversion factor rather than an estimate.
How do I convert astronomical unit to foot?
Multiply the astronomical unit value by 490806662400. The converter above does this instantly to whatever precision you set.
How do I convert foot back to astronomical unit?
Use the reverse factor: 1 foot equals 2.037462e-12 astronomical units. You can also use the swap control in the converter above to flip the direction instantly.
What is a astronomical unit?
Astronomical unit (AU) measures distance. The astronomical unit is defined as exactly 149,597,870,700 meters, close to the average Earth-Sun distance. It is classified as a Non-SI unit accepted for use with SI (astronomical).
What is a foot?
Foot (ft) measures distance. The international foot is defined as exactly 0.3048 meters. It is classified as a US/imperial customary unit.
Is the astronomical unit to foot conversion exact?
Yes. The international foot is defined as exactly 0.3048 meters. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the astronomical unit still used today?
Used internationally in astronomy for solar-system-scale distances.