Convert Barleycorn to Chain
Convert barleycorns to chains instantly. 1 barleycorn = 0.0004208754 chain — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Chain to Barleycorn converter for the reverse conversion.
Units explained
Barleycorn
A barleycorn is an Imperial unit of length equal to one third of an inch (about 8.47 mm). It is the basis of UK shoe sizing and is one of the oldest English length units still in use.
The barleycorn derives from the average length of a grain of barley as a natural reference. Standardised at exactly 1/3 inch by the Statute of Edward II in 1324, which used three barleycorns to define an inch.
Barleycorns are the foundation of UK and US children's shoe sizing — each whole size differs by one barleycorn. Also occasionally referenced in horse-handling and historical English literature.
Standardised in 1324 by the Statute of Edward II at 1/3 inch; the value became exact in 1959 when the inch was fixed at 25.4 mm.
Chain
A chain is an Imperial unit of length equal to 66 feet (20.1168 m), or exactly 4 rods or 100 links. It is the central unit in the Gunter chain-based land-survey system.
Defined by Edmund Gunter in 1620 specifically to make land-area arithmetic easy: 10 square chains = 1 acre exactly. The 66-foot length and 100-link subdivision were chosen so chain measurements could be added decimally.
Chains are the fundamental unit of legacy US public land surveys (the entire US township-and-range system uses chains). Modern survey work generally uses meters or feet, but legacy deeds remain in chains.
Invented by Edmund Gunter in 1620; standardised throughout English and American land survey; became exact via the 1959 International Yard and Pound Agreement.
Barleycorn to Chain conversion formula
The relationship between barleycorns and chains:
To convert barleycorns to chains, multiply the value in barleycorns by 0.0004208754. To reverse, multiply chains by 2375.9999906457.
How to use this converter
Type a value into the calculator. The result in chains updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Chain to Barleycorn converter for the reverse direction.
Step-by-step: convert barleycorns to chains
- Write down the value in barleycorns (barleycorn).
- Multiply that value by the factor 0.0004208754.
- The product is the equivalent value in chains (ch).
- To reverse, multiply the chain value by 2375.9999906457.
Worked examples
Example 1 — Convert 1 barleycorn to ch:
1 × 0.0004208754 = 0.0004208754 ch
Example 2 — Convert 100 barleycorn to ch:
100 × 0.0004208754 = 0.0420875423 ch
Real-world example — Ruler-scale measurements
A 30-barleycorn school ruler converts cleanly to chains — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 barleycorn × 0.0004208754 = 0.0126262627 ch
Real-world example — Hardware-scale dimensions
A 10-barleycorn fastener or component is about as long as a thumbnail. Mechanics and DIY enthusiasts convert between barleycorns and chains daily when mixing metric and imperial tools.
10 barleycorn × 0.0004208754 = 0.0042087542 ch
Real-world example — Postcard and small-object dimensions
A postcard is about 5 barleycorns wide. Converting to chains is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 barleycorn × 0.0004208754 = 0.0021043771 ch
Barleycorn to Chain conversion table
Standard reference values for converting barleycorns to chains:
| Barleycorn [barleycorn] | Chain [ch] |
|---|---|
| 0.01 | 4.208754e-6 |
| 0.1 | 4.208754e-5 |
| 1 | 0.0004208754 |
| 2 | 0.0008417508 |
| 3 | 0.0012626263 |
| 4 | 0.0016835017 |
| 5 | 0.0021043771 |
| 10 | 0.0042087542 |
| 20 | 0.0084175085 |
| 30 | 0.0126262627 |
| 40 | 0.0168350169 |
| 50 | 0.0210437711 |
| 100 | 0.0420875423 |
| 500 | 0.2104377113 |
| 1000 | 0.4208754225 |
Frequently asked questions
How many chains is 1 barleycorn?
How do I convert barleycorns to chains?
How do I convert chains back to barleycorns?
How many chains is 100 barleycorns?
Popular length unit conversions
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Metric / SI (4 units)
Imperial / US Customary (26 units)
Sources & references
Conversion factor (1 barleycorn = 0.0004208754 ch) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.