Convert Microinch to Furlong
Convert microinches to furlongs instantly. 1 microinch = 1.262626e-10 furlong — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Furlong to Microinch converter for the reverse conversion.
Units explained
Microinch
A microinch is an Imperial unit of length equal to one millionth of an inch (2.54×10⁻⁸ m). It is used almost exclusively in surface-finish specifications for precision machining and optical components.
The microinch is derived from the inch using the SI-style prefix micro- to denote one millionth. Standardised through the 1959 International Yard and Pound Agreement, which fixed the inch at exactly 25.4 mm.
Microinches express surface roughness (Ra values) in US-based precision manufacturing — typical machined surfaces are 16–125 µin. Optical components and bearing races are often specified to 1–4 µin Ra.
Used in US precision-manufacturing literature throughout the 20th century; value became exact in 1959 when the inch was fixed at 25.4 mm via the International Yard and Pound Agreement.
Furlong
A furlong is an Imperial unit of length equal to 660 feet, or exactly one eighth of a mile (about 201.17 m). It is the longest unit in the traditional English farm-and-survey system.
The furlong derives from Old English furh (furrow) + lang (long) — originally the length of a furrow in a typical medieval English open field. Standardised at 660 feet (= 10 chains = 220 yards = 1/8 mile) in medieval times.
Furlongs are the standard distance unit in horse racing (e.g., 'The race is 8 furlongs'), historical English farming and surveying, and occasional poetic or rhetorical usage. Modern racing courses worldwide list distances in furlongs.
Medieval English farming origin; standardised at 660 feet; remains the official distance unit in flat-racing thoroughbred horse races worldwide.
Microinch to Furlong conversion formula
The relationship between microinches and furlongs:
To convert microinches to furlongs, multiply the value in microinches by 1.262626e-10. To reverse, multiply furlongs by 7.92e+9.
How to use this converter
Type a value into the calculator. The result in furlongs updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Furlong to Microinch converter for the reverse direction.
Step-by-step: convert microinches to furlongs
- Write down the value in microinches (µin).
- Multiply that value by the factor 1.262626e-10.
- The product is the equivalent value in furlongs (fur).
- To reverse, multiply the furlong value by 7.92e+9.
Worked examples
Example 1 — Convert 1 µin to fur:
1 × 1.262626e-10 = 1.262626e-10 fur
Example 2 — Convert 100 µin to fur:
100 × 1.262626e-10 = 1.262626e-8 fur
Real-world example — Molecular dimensions
The diameter of small molecular structures (around 2 microinches) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.
2 µin × 1.262626e-10 = 2.525253e-10 fur
Real-world example — Wavelengths across the spectrum
Optical and atomic-scale phenomena are routinely cross-converted between sub-micron units. A photon of wavelength 800 microinches can be re-expressed in furlongs for direct comparison with another instrument's calibration data sheet.
800 µin × 1.262626e-10 = 1.010101e-7 fur
Microinch to Furlong conversion table
Standard reference values for converting microinches to furlongs:
| Microinch [µin] | Furlong [fur] |
|---|---|
| 0.01 | 1.262626e-12 |
| 0.1 | 1.262626e-11 |
| 1 | 1.262626e-10 |
| 2 | 2.525253e-10 |
| 3 | 3.787879e-10 |
| 4 | 5.050505e-10 |
| 5 | 6.313131e-10 |
| 10 | 1.262626e-9 |
| 20 | 2.525253e-9 |
| 30 | 3.787879e-9 |
| 40 | 5.050505e-9 |
| 50 | 6.313131e-9 |
| 100 | 1.262626e-8 |
| 500 | 6.313131e-8 |
| 1000 | 1.262626e-7 |
Frequently asked questions
How many furlongs is 1 microinch?
How do I convert microinches to furlongs?
How do I convert furlongs back to microinches?
How many furlongs is 100 microinches?
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Sources & references
Conversion factor (1 µin = 1.262626e-10 fur) 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.