Convert Barleycorn to Inch
Convert barleycorns to inches instantly. 1 barleycorn = 0.3333333346 inch — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Inch 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.
Inch
An inch is an Imperial and US customary unit of length defined since 1959 as exactly 25.4 millimeters (0.0254 meters). It is still the standard small unit of length in the United States, the United Kingdom (informally), and a few other countries.
The inch derives from the Roman uncia (one-twelfth of a foot) and survived through Anglo-Saxon and medieval English measurement systems. Various definitions persisted regionally until the 1959 International Yard and Pound Agreement standardized the inch globally as exactly 25.4 mm.
Inches are used in the US and UK for body height, screen sizes (TVs, monitors, phones), tire sizes, plumbing, lumber, paper sizes (US Letter is 8.5 × 11 in), and most consumer product specifications in the United States.
Anglo-Saxon origin (predating 1066); standardized to 25.4 mm exactly by the International Yard and Pound Agreement of 1959, signed by the US, UK, Canada, Australia, New Zealand, and South Africa.
Barleycorn to Inch conversion formula
The relationship between barleycorns and inches:
To convert barleycorns to inches, multiply the value in barleycorns by 0.3333333346. To reverse, multiply inches by 2.9999999882.
How to use this converter
Type a value into the calculator. The result in inches updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Inch to Barleycorn converter for the reverse direction.
Step-by-step: convert barleycorns to inches
- Write down the value in barleycorns (barleycorn).
- Multiply that value by the factor 0.3333333346.
- The product is the equivalent value in inches (in).
- To reverse, multiply the inch value by 2.9999999882.
Worked examples
Example 1 — Convert 1 barleycorn to in:
1 × 0.3333333346 = 0.3333333346 in
Example 2 — Convert 100 barleycorn to in:
100 × 0.3333333346 = 33.3333334646 in
Real-world example — Ruler-scale measurements
A 30-barleycorn school ruler converts cleanly to inches — useful when buying a desk accessory from a retailer whose product specs use a different unit.
30 barleycorn × 0.3333333346 = 10.0000000394 in
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 inches daily when mixing metric and imperial tools.
10 barleycorn × 0.3333333346 = 3.3333333465 in
Real-world example — Postcard and small-object dimensions
A postcard is about 5 barleycorns wide. Converting to inches is essential for international postal addressing forms that ask for dimensions in different units across countries.
5 barleycorn × 0.3333333346 = 1.6666666732 in
Barleycorn to Inch conversion table
Standard reference values for converting barleycorns to inches:
| Barleycorn [barleycorn] | Inch [in] |
|---|---|
| 0.01 | 0.0033333333 |
| 0.1 | 0.0333333335 |
| 1 | 0.3333333346 |
| 2 | 0.6666666693 |
| 3 | 1.0000000039 |
| 4 | 1.3333333386 |
| 5 | 1.6666666732 |
| 10 | 3.3333333465 |
| 20 | 6.6666666929 |
| 30 | 10.0000000394 |
| 40 | 13.3333333858 |
| 50 | 16.6666667323 |
| 100 | 33.3333334646 |
| 500 | 166.6666673228 |
| 1000 | 333.3333346457 |
Frequently asked questions
How many inches is 1 barleycorn?
How do I convert barleycorns to inches?
How do I convert inches back to barleycorns?
How many inches 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 = 0.3333333346 in) 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.