# Chains to Astronomical Units (ch to au)

Source: https://www.unitconvertercalculator.com/length/chains-to-astronomical-units/

**1 ch = 1.3447250222125E-10 au**

One chain equals approximately 1.345 x 10-10 astronomical units, or about 0.135 billionths of an AU. At 66 feet (20.1168 m), the surveyor's chain is incomprehensibly tiny compared to the Earth-Sun distance of 149.6 million km. This conversion has no practical application.

## Formula

Convert Chains to Astronomical Units

## Conversion Table

| Chains (ch) | Astronomical Units (au) |
|---|---|
| 1 ch | 1.3447250222E-10 au |
| 10 ch | 1.34472502221E-9 au |
| 80 ch | 1.075780017769E-8 au |
| 100 ch | 1.344725022212E-8 au |
| 1000 ch | 1.3447250222124E-7 au |
| 10000 ch | 1.3447250222125E-6 au |
| 100000 ch | 1.3447250222125E-5 au |
| 1000000 ch | 0.00013447250222125 au |
| 10000000 ch | 0.0013447250222125 au |
| 100000000 ch | 0.013447250222125 au |

## Units

### Chain (ch)

Exactly 66 feet or 4 rods (20.1168 m). Invented by Edmund Gunter for land surveying. 80 chains make one mile. Still used in US public land surveys.

### Astronomical Unit (au)

Exactly 149,597,870,700 meters by IAU 2012 definition. Roughly the average distance from the Earth to the Sun. Used for distances within our solar system.

## Background

You would need about 7.43 billion chains laid end to end to reach from Earth to the Sun. The entire US Public Land Survey, conducted in chains, covered only a fraction of the Earth's surface, which itself is a tiny dot at the AU scale. These measurement systems exist in completely separate universes.

## Good to Know

Gunter designed his chain to make land area calculations simple: 10 square chains = 1 acre. The AU was designed to simplify orbital mechanics. Both are elegant solutions to their respective problems, just at scales 10 billion times apart.

## FAQ

### How many AU is 1 chain?

One chain equals approximately 1.345 x 10-10 AU (about 0.135 billionths of an AU). The chain is vanishingly small on the astronomical scale.

### How many chains would it take to reach the Sun?

Approximately 7.43 billion chains (7.43 x 109) placed end to end would span 1 AU, the Earth-Sun distance.

### Is this conversion ever used?

No. Chains measure farm fields and property boundaries. AU measures planetary orbits. They belong to completely separate measurement domains with no overlap.

## Non-Frequently Asked Questions

### How many chains would it take to chain yourself to the Sun?

About 7.4 billion chains (149.6 million km / 20.1 m per chain). You would also need very heat-resistant chain links for the last few million kilometers. Not recommended.

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## See Also

- [Astronomical Units to Chains](https://www.unitconvertercalculator.com/length/astronomical-units-to-chains/)