Length · Unit Converter

Convert Square Mil to Square Chain

Convert square mils to square chains instantly. 1 square mil = 1.594225e-12 square chain — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Chain to Square Mil converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Girish V Kulkarni Ph.D.
Length category 2 min read Published Last reviewed Updated

Units explained

Imperial / US Customary

Square Mil

What is a square mil?

A square mil is an imperial unit of area equal to 6.4516×10⁻¹⁰ m². It is widely used in printed circuit board (PCB) design and electronics manufacturing.

Origin of the square mil

Derived by squaring the mil (1 mil = 1/1000 of an inch = 0.0254 mm). Standardized via the 1959 International Yard and Pound Agreement.

Where it is used

Square mils are the standard unit for PCB trace cross-sections, pad areas, and component pitches in US-localized electronic design software and datasheets.

When and where it was developed

Standardized via the 1959 International Yard and Pound Agreement.

Imperial / US Customary

Square Chain

What is a square chain?

A square chain is an imperial unit of area equal to approximately 404.686 m². It equals 1/10 of an acre.

Origin of the square chain

Derived by squaring the chain (66 feet or 22 yards). The chain was defined by Edmund Gunter in 1620 specifically so that 10 square chains equal exactly one acre.

Where it is used

Square chains appear in US Public Land Survey System (PLSS) records and historical English property documents. The 10-to-1 ratio with acres made early survey arithmetic easier.

When and where it was developed

Defined by Edmund Gunter in 1620 specifically for surveying convenience.

Square Mil to Square Chain conversion formula

The relationship between square mils and square chains:

1 mil² = 1.594225e-12 ch²
1 ch² = 6.27264e+11 mil²

To convert square mils to square chains, multiply the value in square mils by 1.594225e-12. To reverse, multiply square chains by 6.27264e+11.

How to use this converter

Type a value into the calculator. The result in square 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 Square Chain to Square Mil converter for the reverse direction.

Step-by-step: convert square mils to square chains

  1. Write down the value in square mils (mil²).
  2. Multiply that value by the factor 1.594225e-12.
  3. The product is the equivalent value in square chains (ch²).
  4. To reverse, multiply the square chain value by 6.27264e+11.

Worked examples

Example 1 — Convert 1 mil² to ch²:
1 × 1.594225e-12 = 1.594225e-12 ch²

Example 2 — Convert 100 mil² to ch²:
100 × 1.594225e-12 = 1.594225e-10 ch²

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 square mils can be re-expressed in square chains for direct comparison with another instrument's calibration data sheet.

800 mil² × 1.594225e-12 = 1.27538e-9 ch²

Real-world example — Molecular dimensions

The diameter of small molecular structures (around 2 square mils) is often converted into related sub-micron units when comparing measurements across different microscopy techniques or imaging modalities.

2 mil² × 1.594225e-12 = 3.18845e-12 ch²

Square Mil to Square Chain conversion table

Standard reference values for converting square mils to square chains:

Square Mil [mil²]Square Chain [ch²]
0.011.594225e-14
0.11.594225e-13
11.594225e-12
23.18845e-12
34.782675e-12
46.3769e-12
57.971125e-12
101.594225e-11
203.18845e-11
304.782675e-11
406.3769e-11
507.971125e-11
1001.594225e-10
5007.971125e-10
10001.594225e-9

Frequently asked questions

How many square chains is 1 square mil?
1 square mil equals 1.594225e-12 square chain.
How do I convert square mils to square chains?
Multiply the value in square mils by 1.594225e-12 to get square chains.
How do I convert square chains back to square mils?
Multiply the value in square chains by 6.27264e+11, or use the Square Chain to Square Mil converter.
How many square chains is 100 square mils?
100 square mils equals 1.594225e-10 square chains, because 100 × 1.594225e-12 = 1.594225e-10.

Convert Square Mil to other area units

Show all Square Mil conversions

Sources & references

Conversion factor (1 mil² = 1.594225e-12 ch²) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.