Convert Barleycorn to Mil
Convert barleycorns to mils instantly. 1 barleycorn = 333.3333346457 mil — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Mil 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.
Mil
A mil (also called a thou) is an Imperial unit of length equal to one thousandth of an inch (1/1000 in = 0.0254 mm = 25.4 μm exactly). It is used in engineering, manufacturing, and materials specifications.
The mil is derived from the Latin mille, "thousand," denoting one-thousandth of an inch. Standardized in industrial use during the 19th-century rise of precision engineering.
Mils are used to specify thicknesses of plastic films, foils, paper, copper traces on printed circuit boards (PCBs), wire insulation, and paint coatings. A standard sheet of paper is about 4 mils thick.
Adopted in 19th-century engineering practice; the value (1/1000 in) became exact in 1959 when the inch was fixed at 25.4 mm via the International Yard and Pound Agreement. The British term is "thou"; American term is "mil".
Barleycorn to Mil conversion formula
The relationship between barleycorns and mils:
To convert barleycorns to mils, multiply the value in barleycorns by 333.3333346457. To reverse, multiply mils by 0.003.
How to use this converter
Type a value into the calculator. The result in mils updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Mil to Barleycorn converter for the reverse direction.
Step-by-step: convert barleycorns to mils
- Write down the value in barleycorns (barleycorn).
- Multiply that value by the factor 333.3333346457.
- The product is the equivalent value in mils (mil).
- To reverse, multiply the mil value by 0.003.
Worked examples
Example 1 — Convert 1 barleycorn to mil:
1 × 333.3333346457 = 333.3333346457 mil
Example 2 — Convert 100 barleycorn to mil:
100 × 333.3333346457 = 33333.3334645669 mil
Real-world example — Adjacent small-scale precision
One barleycorn equals 1,000 mils — the standard sub-millimeter precision conversion that materials engineers use whenever they switch between bulk material thickness specs (larger unit) and surface-finish characteristics (smaller unit).
1 barleycorn × 333.3333346457 = 333.3333346457 mil
Real-world example — Adjacent metric sub-units
One barleycorn equals 1,000 mils. Engineers move between these scales constantly: PCB feature sizes in the larger unit, wire-bond diameters in the smaller.
1 barleycorn × 333.3333346457 = 333.3333346457 mil
Barleycorn to Mil conversion table
Standard reference values for converting barleycorns to mils:
| Barleycorn [barleycorn] | Mil [mil] |
|---|---|
| 0.01 | 3.3333333465 |
| 0.1 | 33.3333334646 |
| 1 | 333.3333346457 |
| 2 | 666.6666692913 |
| 3 | 1000.000003937 |
| 4 | 1333.3333385827 |
| 5 | 1666.6666732283 |
| 10 | 3333.3333464567 |
| 20 | 6666.6666929134 |
| 30 | 10000.0000393701 |
| 40 | 13333.3333858268 |
| 50 | 16666.6667322835 |
| 100 | 33333.3334645669 |
| 500 | 166666.6673228347 |
| 1000 | 333333.3346456693 |
Frequently asked questions
How many mils is 1 barleycorn?
How do I convert barleycorns to mils?
How do I convert mils back to barleycorns?
How many mils 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 = 333.3333346457 mil) 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 Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.