Convert length and distance units — meters, feet, inches, kilometers, miles, light years and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 chain | 1.345e-13 au | |
| 0.01 chain | 1.345e-12 au | |
| 0.1 chain | 1.345e-11 au | |
| 1 chain | 1.345e-10 au | |
| 5 chain | 6.724e-10 au | |
| 10 chain | 1.34471e-09 au | |
| 50 chain | 6.72353e-09 au | |
| 100 chain | 1.34471e-08 au | |
| 1000 chain | 1.34471e-07 au |
Multiply the number of Chains by 1.3447×10-10 to get Astronomical Units. Formula: au = chain × 1.3447×10-10. Example: 10 chain × 1.3447×10-10 = 1.3447×10-9 au. To reverse, divide Astronomical Units by 1.3447×10-10 to get Chains.
| Chain (chain) | Astronomical Unit (au) |
|---|---|
| 0.001 chain | 1.3447×10-13 au |
| 0.01 chain | 1.3447×10-12 au |
| 0.1 chain | 1.3447×10-11 au |
| 0.5 chain | 6.7235×10-11 au |
| 1 chain | 1.3447×10-10 au |
| 2 chain | 2.6894×10-10 au |
| 5 chain | 6.7235×10-10 au |
| 10 chain | 1.3447×10-9 au |
| 20 chain | 2.6894×10-9 au |
| 50 chain | 6.7235×10-9 au |
| 100 chain | 1.3447×10-8 au |
| 250 chain | 3.3618×10-8 au |
| 500 chain | 6.7235×10-8 au |
| 1000 chain | 1.34471e-07 au |
| 10000 chain | 1.34471e-06 au |
To convert Chain to Astronomical Unit, multiply by 1.3447×10-10. Example: 10 chain = 1.3447×10-9 au
To convert Astronomical Unit back to Chain, divide by 1.3447×10-10 (multiply by 7436570000). Use the swap button above.
Start with 100 Chains = 1.3447×10-8 au as your reference point. Scale up or down from there.
1 chain = 1.345×10⁻¹⁰ AU — a fraction so small it requires scientific notation. Science educators use chain-to-AU to illustrate the full span of human measurement: from the length of a ploughed furrow to the Earth-Sun distance.
Edmund Gunter invented the chain in 1620. The astronomical unit was formalised in 1976. These two units — spanning 356 years of measurement history — represent the evolution from practical land administration to space-age science.
University physics courses use unusual cross-domain conversions like chain-to-AU in dimensional analysis problem sets, testing students' ability to chain multiple conversion factors and work confidently with scientific notation.
Science communicators occasionally use chain-to-AU comparisons to explain astronomical scales with unexpected whimsy: "The Earth-Sun distance is 7.4 billion chains — enough to fence off every farm in England 10,000 times."
Geodesists working with both historical land survey records (in chains) and modern satellite geodesy referenced to AU-scale orbital parameters need cross-scale unit conversion in archival research.
Complete length unit databases include chain-to-AU for scientific and historical completeness — ensuring researchers encounter no gaps when working across disciplines that use different historical measurement traditions.
The Chain is a unit of Length measurement (symbol: chain). 1 chain = 1.3447×10-10 au. Used in scientific and practical Length measurement applications.
The Astronomical Unit is a unit of Length measurement (symbol: au). It is part of an internationally recognised measurement system used alongside the Chain.
Edmund Gunter invented the surveyor's chain in 1620. His design — 100 links totalling exactly 66 feet — was brilliantly chosen: 10 chains × 10 chains = 1 acre, making area calculation trivially simple in the field. 80 chains = 1 mile, 10 chains = 1 furlong. The chain became standard across the British Empire and is written into American law — the US Public Land Survey System still divides land using chains and links.
The astronomical unit has ancient roots — Aristarchus of Samos attempted to measure the Earth-Sun distance around 270 BC, estimating it at 18–20 lunar distances (the true value is about 390). For centuries the AU was estimated using Venus transit observations and trigonometry. Edmond Halley organised the first coordinated international transit-of-Venus expedition in 1716. The modern value was determined by radar ranging to Venus in 1961. The IAU formally defined the AU as exactly 149,597,870,700 metres in 2012 — a fixed constant of physics, not a measured distance.
Common use: Chain to Astronomical Unit conversion is needed when working with international standards, scientific publications, or reference materials that use different unit systems for Length measurement.