Instant · Precise · Universal
23 units available
6 categories total
To convert mm² to cm²: divide by 100. To in²: multiply by 0.00155.
1 mm² = 0.01 cm² = 10⁻⁶ m². There are 1,000,000 mm² in 1 m².
For example, 1 Square Millimeter (mm²) = 3.861006e-13 Square Mile (US Survey) (mi² (US)).
| Square Millimeter (mm²) | Square Mile (US Survey) (mi² (US)) |
|---|---|
| 0.1 | 3.861006e-14 |
| 0.5 | 1.930503e-13 |
| 1 | 3.861006e-13 |
| 2 | 7.722012e-13 |
| 5 | 1.930503e-12 |
| 10 | 3.861006e-12 |
| 25 | 9.652515e-12 |
| 50 | 1.930503e-11 |
| 100 | 3.861006e-11 |
| 500 | 1.930503e-10 |
| 1000 | 3.861006e-10 |
The square millimeter is a metric unit of area equal to 10⁻⁶ square meters, or the area of a square 1 mm on each side.
1 mm² = 0.01 cm² = 10⁻⁶ m². There are 1,000,000 mm² in 1 m².
To convert mm² to cm²: divide by 100. To in²: multiply by 0.00155.
Wire gauge cross-sections, solder pad sizes on PCBs, precision machined surface areas, and needle gauges.
A standard 14 AWG electrical wire has a cross-section of about 2.08 mm². The period at the end of this sentence covers about 0.25 mm².
Confusing mm² with mm — wire is specified by cross-sectional area (mm²), not diameter. A 2.5 mm² wire has ~1.78 mm diameter.
In Europe, electrical wire is sized by mm² (cross-section area). The US uses AWG gauge numbers instead.
The US survey square mile is a historical area unit based on the US survey foot, equal to approximately 2,589,998.47 m².
1 mi² (US) ≈ 2,589,998.47 m². Differs from international mi² (2,589,988.11 m²) by about 10.36 m².
To convert US survey mi² to km²: multiply by 2.590. To international mi²: multiply by ~1.000004.
Historical US Public Land Survey System sections (each nominally 1 mi² US survey).
Over one square mile, the US survey definition differs from the international definition by about 10.4 m² — roughly a 3 m × 3.5 m room.
Using the US survey mile for new calculations. Deprecated since 2023 — use the international definitions.
The US Survey system was a legacy from 1893. Its 2023 retirement unified US measurements with the international standard.



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