Foot to Light Year Converter
Convert Foot (ft) to Light Year (ly) instantly. 1 ft = 3.221739e-17 ly.
Length Converter
31 units available
1 ft = 3.221739e-17 ly
Formula:
ly = ft × 3.221739e-17With your value: 1 ft = 3.221739e-17 ly
How big is that?
Everyday references on a logarithmic scale, all expressed in foot so you can sanity-check the result.
Other Foot to Light Year conversions
Foot to Light Year Conversion Table
| Foot (ft) | Light Year (ly) |
|---|---|
| 0.5 | 1.610869e-17 |
| 1 | 3.221739e-17 |
| 2 | 6.443477e-17 |
| 5 | 1.610869e-16 |
| 10 | 3.221739e-16 |
| 15 | 4.832608e-16 |
| 20 | 6.443477e-16 |
| 25 | 8.054346e-16 |
| 50 | 1.610869e-15 |
| 100 | 3.221739e-15 |
| 250 | 8.054346e-15 |
| 500 | 1.610869e-14 |
| 1000 | 3.221739e-14 |
Light Year to Foot Conversion Table
| Light Year (ly) | Foot (ft) |
|---|---|
| 0.5 | 1.551957e+16 |
| 1 | 3.103914e+16 |
| 2 | 6.207828e+16 |
| 5 | 1.551957e+17 |
| 10 | 3.103914e+17 |
| 15 | 4.655871e+17 |
| 20 | 6.207828e+17 |
| 25 | 7.759785e+17 |
| 50 | 1.551957e+18 |
| 100 | 3.103914e+18 |
| 250 | 7.759785e+18 |
| 500 | 1.551957e+19 |
| 1000 | 3.103914e+19 |
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.
Foot (ft)
Length
1 foot = 0.3048 m exactly (international foot, 1959).
The US survey foot (1200/3937 m) was deprecated for new work on 31 December 2022 and differs by about 2 ppm.
Source: International Yard and Pound Agreement of 1959; NIST Federal Register Notice 59-5442
US, UK, Canada, Australia, New Zealand, South Africa · Reviewed 2026-07-01
Light Year (ly)
Length
A light-year is the distance light travels in one Julian year: 9 460 730 472 580 800 m exactly.
Source: IAU Resolution B2 (2012) — definition of the astronomical unit; IAU B2 (2015) nominal values
International Astronomical Union · Reviewed 2026-07-01
How to Convert Foot to Light Year
To convert from Foot (ft) to Light Year (ly), multiply the value by 3.221739e-17.
Formula: ly = ft × 3.221739e-17
Reverse: ft = ly × 3.103914e+16
Step-by-Step Example
- Start with your value in Foot. For example: 5 ft
- Multiply by the conversion factor: 5 x 3.221739e-17
- The result is: 1.610869e-16 ly
About Foot
The foot is an imperial unit equal to 12 inches or 0.3048 meters. It remains widely used in the US, UK, and Canada for everyday measurements.
Fun Fact: The foot was originally based on the length of a human foot, which varied from region to region.
Common uses: height measurement, real estate, construction.
About Light Year
A light year is the distance light travels through a vacuum in one Julian year — exactly 9,460,730,472,580,800 metres. It is a unit of distance, not of time.
Fun Fact: Proxima Centauri, the nearest star to the Sun, sits about 4.25 light years away.
Common uses: astronomy, popular science, education.
Frequently Asked Questions
How many Light Year are in 1 Foot?
There are exactly 3.221739e-17 Light Year in 1 Foot. This means the conversion factor from Foot to Light Year is 3.221739e-17.
What is the formula to convert Foot to Light Year?
The formula to convert Foot to Light Year is: ly = ft × 3.221739e-17. For example, to convert 10 Foot to Light Year, you would multiply 10 by 3.221739e-17.
What is a Foot?
The foot is an imperial unit equal to 12 inches or 0.3048 meters. It remains widely used in the US, UK, and Canada for everyday measurements.
What is a Light Year?
A light year is the distance light travels through a vacuum in one Julian year — exactly 9,460,730,472,580,800 metres. It is a unit of distance, not of time.
What are the common uses of Foot?
The Foot is commonly used in height measurement, real estate, construction.
Related Length Conversions
Cite this page
UnitConvertLab. (2026). Foot to Light Year converter. UnitConvertLab. Retrieved from https://unitconvertlab.com/convert/foot-to-light_year