---
title: "Feet to Light-years — ft to ly converter"
description: "1 foot = 3.222 × 10^-17 light-years. Convert feet to light-years with a full conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/feet-to-light-years/
site: "At One Place"
---

# Feet to light-years

**1 foot in light-years: 1 ft = 3.222 × 10^-17 ly**

ly = ft × 3.221738542 × 10^-17

To convert feet to light-years, multiply by 3.221738542 × 10^-17. The table below gives the values people look up most often, and the converter works for any number.

## Feet to light-years table

*Common foot values converted to light-years.*

| Feet | Light-years |
| --- | --- |
| 1 ft | 3.222 × 10^-17 |
| 2 ft | 6.443 × 10^-17 |
| 3 ft | 9.665 × 10^-17 |
| 4 ft | 1.289 × 10^-16 |
| 5 ft | 1.611 × 10^-16 |
| 10 ft | 3.222 × 10^-16 |
| 15 ft | 4.833 × 10^-16 |
| 20 ft | 6.443 × 10^-16 |
| 25 ft | 8.054 × 10^-16 |
| 30 ft | 9.665 × 10^-16 |
| 40 ft | 1.289 × 10^-15 |
| 50 ft | 1.611 × 10^-15 |
| 75 ft | 2.416 × 10^-15 |
| 100 ft | 3.222 × 10^-15 |
| 250 ft | 8.054 × 10^-15 |
| 500 ft | 1.611 × 10^-14 |
| 1,000 ft | 3.222 × 10^-14 |

## How the conversion works

The relationship is ly = ft × 3.221738542 × 10^-17. Both units measure length, so the conversion is a fixed factor that never changes. The figure is exact rather than approximate: since the international yard and pound agreement of 1959, an inch is defined as exactly 25.4 millimetres and a pound as exactly 0.45359237 kilograms, and every other imperial and US customary unit here is derived from those two.

> Foot: Plural is "feet".

## Common questions

### How many light-years are in one foot?

One foot equals 3.222 × 10^-17 light-years. ly = ft × 3.221738542 × 10^-17.

### How do you convert feet to light-years?

Use ly = ft × 3.221738542 × 10^-17. So 10 ft is 3.222 × 10^-16 ly.

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

One light-year equals 3.1039142 × 10^16 feet, which is the reverse of the conversion above.

### Is there more than one kind of foot?

Plural is "feet".

## Related pages

- [Light-years to Feet](https://atoneplace.net/convert/light-years-to-feet/)
- [Feet to Meters](https://atoneplace.net/convert/feet-to-meters/)
- [Feet to Kilometers](https://atoneplace.net/convert/feet-to-km/)
- [Feet to Centimeters](https://atoneplace.net/convert/feet-to-cm/)
- [Feet to Millimeters](https://atoneplace.net/convert/feet-to-mm/)
- [Feet to Miles](https://atoneplace.net/convert/feet-to-miles/)
- [Feet to Yards](https://atoneplace.net/convert/feet-to-yards/)
- [Feet to Inches](https://atoneplace.net/convert/feet-to-inches/)

## Sources

- Guide for the Use of the International System of Units (SP 811) — NIST (https://www.nist.gov/pml/special-publication-811) [Public domain (US Government)]
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures (https://www.bipm.org/en/publications/si-brochure)
- Calculated on this page — At One Place (/about/)