A foot is exactly 0.3048 meters.
Feet to Astronomical units Converter — ft to AU
Convert Foot (ft) to Astronomical unit (AU) using the exact conversion factor (1 foot = 2.037462e-12 astronomical unit). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Feet to Astronomical units 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.
An astronomical unit is the mean Earth-Sun distance.
Result = input x 0.3048 / 1.49597871e+11.
Length uses the meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Feet to Astronomical units
Foot and Astronomical unit both measure length. Foot is typically associated with united States (height, construction, aviation altitude), while Astronomical unit is typically associated with used internationally in astronomy for solar-system-scale distances..
Formula
astronomical units = feet × 2.037462e-12
This factor comes from each unit's defined relationship to the category's base unit: 1 foot equals 0.3048 base units, and 1 astronomical unit equals 149597870700 base units, so dividing one by the other gives the direct foot-to-astronomical unit factor of 2.037462e-12.
Simple example
1 ft × 2.037462e-12 = 2.037462e-12 AU
1 foot = 2.037462e-12 astronomical units.
Real-world example
10 ft × 2.037462e-12 = 2.037462e-11 AU
10 feet = 2.037462e-11 astronomical units.
Conversion table
| Foot (ft) | Astronomical unit (AU) |
|---|---|
| 1 ft | 2.037462e-12 AU |
| 5 ft | 1.018731e-11 AU |
| 10 ft | 2.037462e-11 AU |
| 21.0975 ft | 4.298536e-11 AU |
| 42.195 ft | 8.597072e-11 AU |
| 100 ft | 2.037462e-10 AU |
Reverse conversion: Astronomical unit to Foot
2.037462e-12 AU × 490806662400 = 0.999999924 ft
2.037462e-12 astronomical units = 0.999999924 feet.
feet = astronomical units × 490806662402
For a page dedicated to this direction, see Astronomical unit to Foot.
Foot vs. Astronomical unit
| Aspect | Foot | Astronomical unit |
|---|---|---|
| Family | US/imperial customary unit | Non-SI unit accepted for use with SI (astronomical) |
| Typical use | Height measurement in the US and UK | Measuring distances within the solar system (planetary orbits) |
| Where it's used | United States (height, construction, aviation altitude) | Used internationally in astronomy for solar-system-scale distances. |
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.
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.
Foot — sources
- NIST — International yard and pound (1959) — Fixes the modern foot at exactly 0.3048 meters.
Astronomical unit — sources
- IAU Resolution B2 (2012) — Fixes the astronomical unit at exactly 149,597,870,700 meters.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many astronomical units are in 1 foot?
1 foot equals 2.037462e-12 astronomical units, using the exact defined conversion factor rather than an estimate.
How do I convert foot to astronomical unit?
Multiply the foot value by 2.037462e-12. The converter above does this instantly to whatever precision you set.
How do I convert astronomical unit back to foot?
Use the reverse factor: 1 astronomical unit equals 490,806,662,400 feet. You can also use the swap control in the converter above to flip the direction instantly.
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.
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).
Is the foot to astronomical unit conversion exact?
Yes. The astronomical unit is defined as exactly 149,597,870,700 meters, close to the average Earth-Sun distance. 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 foot still used today?
United States (height, construction, aviation altitude) United Kingdom (height, some construction contexts)