Instant · Precise · Universal
23 units available
6 categories total
To convert circular inches to in²: multiply by 0.7854. To cm²: multiply by 5.067.
1 circular inch = π/4 in² ≈ 0.7854 in² ≈ 5.067 cm². Equals 1,000,000 circular mils.
For example, 1 Circular Inch (circ in) = 1.956409e-10 Section (section).
| Circular Inch (circ in) | Section (section) |
|---|---|
| 0.1 | 1.956409e-11 |
| 0.5 | 9.782043e-11 |
| 1 | 1.956409e-10 |
| 2 | 3.912817e-10 |
| 5 | 9.782043e-10 |
| 10 | 1.956409e-9 |
| 25 | 4.891021e-9 |
| 50 | 9.782043e-9 |
| 100 | 1.956409e-8 |
| 500 | 9.782043e-8 |
| 1000 | 1.956409e-7 |
The circular inch is the area of a circle one inch in diameter, equal to π/4 square inches (approximately 0.0005067 m²).
1 circular inch = π/4 in² ≈ 0.7854 in² ≈ 5.067 cm². Equals 1,000,000 circular mils.
To convert circular inches to in²: multiply by 0.7854. To cm²: multiply by 5.067.
Wire and cable cross-section calculations, especially for large conductors in power distribution.
The circular mil and circular inch exist solely to avoid π in cross-section math. Diameter² (in circular units) directly gives the area.
Confusing circular inch with square inch — a circular inch is about 78.5% of a square inch.
For a circle: area in circular inches = diameter². Area in square inches = diameter² × π/4. The circular unit absorbs the π/4 factor.
A section is a unit of land area equal to 1 square mile (640 acres or 2.59 km²), used in the US Public Land Survey System.
1 section = 1 mi² = 640 acres = 2.59 km². 36 sections = 1 township.
To convert sections to acres: multiply by 640. To km²: multiply by 2.59.
Rural property descriptions, agricultural land division, mineral rights, and road grid planning in the western US.
Section 16 in every township was traditionally reserved for public schools — a major source of early American education funding.
Forgetting that sections are numbered in a specific serpentine pattern within a township (1 in NE, snaking to 36).
The US west of Ohio is largely divided into a grid of 1-mile sections. Look at Google Maps in rural areas to see the grid patterns.



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