Mil Circular Mil Area

Overview

Engineering reference data for Mil Circular Mil Area in miscellaneous.

Key Formulas

Unit Conversion

$y = x \cdot k$

Multiply by conversion factor.

Linear Interpolation

$y = y_1 + \frac{(x - x_1)(y_2 - y_1)}{x_2 - x_1}$

Estimate between two known points.

Percentage

$p = \frac{\text{part}}{\text{whole}} \times 100\%$

Part as fraction of whole.

Variables

Symbol	Description	Unit
$x$	Input value	—
$y$	Output value	—
$k$	Conversion factor	—

Unit Conversions

The square mil is the area of a square whose sides are one mil (1 × 10⁻³ inch):

$\text{One Square Mil} = (1 \times 10^{-3})^2 = 1 \times 10^{-6} \text{ in}^2$

Conversion Factors

Imperial Conversions:

From	To	Factor
1 circular mil	square inches	$0.7854 \times 10^{-6}$
1 circular mil	square mils	$0.7854$
1 square mil	circular mils	$1.27$

Metric Conversions:

From	To	Factor
1 circular mil	m²	$5.066 \times 10^{-10}$
1 circular mil	cm²	$5.066 \times 10^{-6}$
1 m²	circular mils	$1.974 \times 10^{9}$
1 cm²	circular mils	$1.974 \times 10^{5}$

Key Relationship

The circular mil area is derived from the square of the diameter in mils, which simplifies calculations for round conductors by eliminating the need for π/4 in the area formula:

$A_{\text{CM}} = d_{\text{mils}}^2$

This contrasts with standard circular area calculations where $A = \frac{\pi}{4} d^2$. The circular mil system inherently accounts for the circular geometry through the conversion factor (0.7854 ≈ π/4) when converting to square units.

References

• Original Source