---
title: "Light-years to Inches — ly to in converter"
description: "1 light-year = 3.724697 × 10^17 inches. Convert light-years to inches with a full conversion table, the exact formula, and a calculator for any value."
url: https://atoneplace.net/convert/light-years-to-inches/
site: "At One Place"
---

# Light-years to inches

**1 light-year in inches: 1 ly = 3.724697 × 10^17 in**

in = ly × 3.724697036 × 10^17

To convert light-years to inches, multiply by 3.724697036 × 10^17. The table below gives the values people look up most often, and the converter works for any number.

## Light-years to inches table

*Common light-year values converted to inches.*

| Light-years | Inches |
| --- | --- |
| 1 ly | 3.724697 × 10^17 |
| 2 ly | 7.4493941 × 10^17 |
| 3 ly | 1.1174091 × 10^18 |
| 4 ly | 1.4898788 × 10^18 |
| 5 ly | 1.8623485 × 10^18 |
| 10 ly | 3.724697 × 10^18 |
| 15 ly | 5.5870456 × 10^18 |
| 20 ly | 7.4493941 × 10^18 |
| 25 ly | 9.3117426 × 10^18 |
| 30 ly | 1.1174091 × 10^19 |
| 40 ly | 1.4898788 × 10^19 |
| 50 ly | 1.8623485 × 10^19 |
| 75 ly | 2.7935228 × 10^19 |
| 100 ly | 3.724697 × 10^19 |
| 250 ly | 9.3117426 × 10^19 |
| 500 ly | 1.8623485 × 10^20 |
| 1,000 ly | 3.724697 × 10^20 |

## How the conversion works

The relationship is in = ly × 3.724697036 × 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.

## Common questions

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

One light-year equals 3.724697 × 10^17 inches. in = ly × 3.724697036 × 10^17.

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

Use in = ly × 3.724697036 × 10^17. So 10 ly is 3.724697 × 10^18 in.

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

One inch equals 2.685 × 10^-18 light-years, which is the reverse of the conversion above.

## Related pages

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

## 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/)