# Feet to Light-years (ft to ly)

Source: https://www.unitconvertercalculator.com/length/feet-to-light-years/

**1 ft = 3.221738542107E-17 ly**

One foot equals approximately 3.222 x 10-17 light-years. Even the tallest building on Earth (Burj Khalifa at 2,717 feet) is only 8.75 x 10-14 light-years tall. The foot measures human-scale heights; the light-year measures interstellar distances. About 16 orders of magnitude separate them.

## Formula

Convert Feet to Light-years

## Conversion Table

| Feet (ft) | Light-years (ly) |
|---|---|
| 1 ft | 3.221E-17 ly |
| 100 ft | 3.22173E-15 ly |
| 10000 ft | 3.2217385E-13 ly |
| 1000000 ft | 3.221738542E-11 ly |
| 100000000 ft | 3.2217385421E-9 ly |
| 10000000000 ft | 3.221738542107E-7 ly |
| 1000000000000 ft | 3.221738542107E-5 ly |
| 100000000000000 ft | 0.003221738542107 ly |
| 10000000000000000 ft | 0.3221738542107 ly |

## Units

### Foot (ft)

An imperial unit of length equal to 12 inches or 0.3048 meters. Used in the US and UK for height, altitude, and construction.

### Light-year (ly)

The distance light travels in one Julian year (365.25 days) in vacuum. Exactly 9,460,730,472,580,800 meters. Used for interstellar distances.

## Background

A light-year contains about 3.104 x 1016 feet (about 31 quadrillion). The nearest star at 4.24 light-years is roughly 1.316 x 1017 feet away. Even Mount Everest at 29,032 feet is only 9.35 x 10-13 light-years tall. Human-scale heights are invisibly small at cosmic distances.

## Good to Know

When Carl Sagan said space is incomprehensibly vast, the foot-to-light-year conversion proves it. Even stacking every building on Earth wouldn't reach a millionth of a light-year. The cosmos operates on a scale that feet simply cannot describe.

## FAQ

### How many light-years is 1 foot?

One foot equals approximately 3.222 x 10-17 light-years. This is a number so small it has no physical meaning at stellar scales.

### How many feet are in 1 light-year?

One light-year contains approximately 3.104 x 1016 feet (about 31 quadrillion feet).

### Is this conversion ever used?

Only in popular science to create vivid scale comparisons. 'The nearest star is 131 quadrillion feet away' helps Americans conceptualize the vastness of space.

## Non-Frequently Asked Questions

### How many feet per second does light travel?

Light travels about 983,571,056 feet per second (983 million). In one second, light covers nearly a billion feet. In a year, that adds up to about 3.104 x 1016 feet (31 quadrillion). The speed of light sounds less impressive in miles (186,282/s) than in feet (983 million/s).

### If Usain Bolt ran at the speed of light, how many feet per race?

The 100-meter dash (328 feet) at light speed would take 3.34 x 10-7 seconds (334 nanoseconds). In that time, Bolt would not even see the starting gun flash arrive at his eyes. Running at light speed makes the race invisible to the runner.

### How long is a light-foot?

A light-foot is the time it takes light to travel 1 foot: about 1.017 nanoseconds. Your computer processor cycles at roughly this speed. So in computer terms, light travels one foot per clock cycle. Your processor thinks in feet of light.

## Related Articles

- [Why We Measure: The Deepest Urge in Human Civilisation](https://www.unitconvertercalculator.com/blog/why-we-measure)
- [The Map Is Not the Territory: Why Every Measurement Is Wrong](https://www.unitconvertercalculator.com/blog/the-map-is-not-the-territory)
- [Zero: The Most Dangerous Number in Measurement](https://www.unitconvertercalculator.com/blog/zero-the-most-dangerous-number-in-measurement)
- [The Body as a Ruler: Every Measurement Unit That Came From Us](https://www.unitconvertercalculator.com/blog/the-body-as-a-ruler)
- [The Speed of Everything: How We Measure From Glaciers to Light](https://www.unitconvertercalculator.com/blog/the-speed-of-everything)
- [15 Obscure Measurement Units You've Never Heard Of (But Still Need)](https://www.unitconvertercalculator.com/blog/obscure-measurement-units-guide)
- [When Measurements Go Wrong - Disasters, Blunders and Happy Accidents](https://www.unitconvertercalculator.com/blog/when-measurements-go-wrong)
- [The Surprising Stories Behind Everyday Units of Measurement](https://www.unitconvertercalculator.com/blog/stories-behind-measurement-units)
- [Metric vs. Imperial - The Complete Guide to the World's Two Measurement Systems](https://www.unitconvertercalculator.com/blog/metric-vs-imperial-complete-guide)
- [Length & Distance Conversion Guide - Meters, Feet, Miles & Kilometers](https://www.unitconvertercalculator.com/blog/length-and-distance-guide)

## See Also

- [Light-years to Feet](https://www.unitconvertercalculator.com/length/light-years-to-feet/)