To convert square inches to circular mils, multiply the value by 1,273,240. To go the other way, multiply circular mils by 7.85398 × 10⁻⁷ to get square inches.
| Square Inches (in²) | Circular Mils (cmil) |
|---|---|
| 1 in² | 1,273,240 cmil |
| 2 in² | 2,546,480 cmil |
| 5 in² | 6,366,200 cmil |
| 10 in² | 12,732,400 cmil |
| 20 in² | 25,464,800 cmil |
| 50 in² | 63,662,000 cmil |
| 100 in² | 127,324,000 cmil |
| 500 in² | 636,620,000 cmil |
| 1,000 in² | 1,273,240,000 cmil |
250 in² × 1,273,240 = 318,310,000 cmil
Try this example →Square inch (in²). A square inch is the area of a square with 1-inch sides (6.4516 cm²).
Circular mil (cmil). A circular mil is the area of a circle 0.001 inch across, the standard measure of wire cross-section in American Wire Gauge.
There are 1,273,240 circular mils in one square inch.
Multiply the number of square inches by 1,273,240. For example, 10 square inches equal 12,732,400 circular mils.
One circular mil equals 7.85398 × 10⁻⁷ square inches.