Convert Square Mile to Square Mil
Convert square miles to square mils instantly. 1 square mile = 4.01449e+15 square mil — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Square Mil to Square Mile converter for the reverse conversion.
Units explained
Square Mile
A square mile is an imperial unit of area equal to exactly 2,589,988.110336 m². It is used for measuring large land areas in the United States and the United Kingdom.
Derived by squaring the statute mile (5,280 feet). The mile was standardized via the 1959 International Yard and Pound Agreement.
Square miles are used for US and UK regional geography (county areas, lake sizes, large parks), national statistics, and military range descriptions. 1 mi² = 640 acres = 2.589988 km².
Mile dates to Roman antiquity; modern exact value standardized in 1959.
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.
Derived by squaring the mil (1 mil = 1/1000 of an inch = 0.0254 mm). Standardized via the 1959 International Yard and Pound Agreement.
Square mils are the standard unit for PCB trace cross-sections, pad areas, and component pitches in US-localized electronic design software and datasheets.
Standardized via the 1959 International Yard and Pound Agreement.
Square Mile to Square Mil conversion formula
The relationship between square miles and square mils:
To convert square miles to square mils, multiply the value in square miles by 4.01449e+15. To reverse, multiply square mils by 2.490977e-16.
How to use this converter
Type a value into the calculator. The result in square mils 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 Mil to Square Mile converter for the reverse direction.
Step-by-step: convert square miles to square mils
- Write down the value in square miles (mi²).
- Multiply that value by the factor 4.01449e+15.
- The product is the equivalent value in square mils (mil²).
- To reverse, multiply the square mil value by 2.490977e-16.
Worked examples
Example 1 — Convert 1 mi² to mil²:
1 × 4.01449e+15 = 4.01449e+15 mil²
Example 2 — Convert 100 mi² to mil²:
100 × 4.01449e+15 = 4.01449e+17 mil²
Square Mile to Square Mil conversion table
Standard reference values for converting square miles to square mils:
| Square Mile [mi²] | Square Mil [mil²] |
|---|---|
| 0.01 | 4.01449e+13 |
| 0.1 | 4.01449e+14 |
| 1 | 4.01449e+15 |
| 2 | 8.028979e+15 |
| 3 | 1.204347e+16 |
| 4 | 1.605796e+16 |
| 5 | 2.007245e+16 |
| 10 | 4.01449e+16 |
| 20 | 8.028979e+16 |
| 30 | 1.204347e+17 |
| 40 | 1.605796e+17 |
| 50 | 2.007245e+17 |
| 100 | 4.01449e+17 |
| 500 | 2.007245e+18 |
| 1000 | 4.01449e+18 |
Frequently asked questions
How many square mils is 1 square mile?
How do I convert square miles to square mils?
How do I convert square mils back to square miles?
How many square mils is 100 square miles?
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Metric / SI (5 units)
Imperial / US Customary (14 units)
Sources & references
Conversion factor (1 mi² = 4.01449e+15 mil²) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.