Convert Chain to Microinch
Convert chains to microinches instantly. 1 chain = 7.92e+8 microinch — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Microinch to Chain converter for the reverse conversion.
Units explained
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.
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.
Chain to Microinch conversion formula
The relationship between chains and microinches:
To convert chains to microinches, multiply the value in chains by 7.92e+8. To reverse, multiply microinches by 1.262626e-9.
How to use this converter
Type a value into the calculator. The result in microinches updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Microinch to Chain converter for the reverse direction.
Step-by-step: convert chains to microinches
- Write down the value in chains (ch).
- Multiply that value by the factor 7.92e+8.
- The product is the equivalent value in microinches (µin).
- To reverse, multiply the microinch value by 1.262626e-9.
Worked examples
Example 1 — Convert 1 ch to µin:
1 × 7.92e+8 = 7.92e+8 µin
Example 2 — Convert 100 ch to µin:
100 × 7.92e+8 = 7.92e+10 µin
Chain to Microinch conversion table
Standard reference values for converting chains to microinches:
| Chain [ch] | Microinch [µin] |
|---|---|
| 0.01 | 7920000.0000000009 |
| 0.1 | 7.92e+7 |
| 1 | 7.92e+8 |
| 2 | 1.584e+9 |
| 3 | 2.376e+9 |
| 4 | 3.168e+9 |
| 5 | 3.96e+9 |
| 10 | 7.92e+9 |
| 20 | 1.584e+10 |
| 30 | 2.376e+10 |
| 40 | 3.168e+10 |
| 50 | 3.96e+10 |
| 100 | 7.92e+10 |
| 500 | 3.96e+11 |
| 1000 | 7.92e+11 |
Frequently asked questions
How many microinches is 1 chain?
How do I convert chains to microinches?
How do I convert microinches back to chains?
How many microinches is 100 chains?
Popular length unit conversions
Convert Chain to other length units
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Metric / SI (4 units)
Imperial / US Customary (26 units)
Sources & references
Conversion factor (1 ch = 7.92e+8 µin) 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.