square foot to square mile
Convert square foot (ft²) to square mile (mi²). Use an editable area converter, conversion formula, and reference table.
1 ft² = 3.58700643e-8 mi²
Conversion formula
One square foot equals 3.58700643e-8 square mile. Multiply your value in square foot by this factor to get square mile. For the reverse conversion, divide by the same factor.
Worked example
To convert 5 square foot:5 × 3.58700643e-8 = 1.79350321e-7 mi²
Conversion table
| square foot (ft²) | square mile (mi²) |
|---|---|
| 0.01 | 3.58700643e-10 |
| 0.1 | 3.58700643e-9 |
| 1 | 3.58700643e-8 |
| 2 | 7.17401286e-8 |
| 5 | 1.79350321e-7 |
| 10 | 3.58700643e-7 |
| 25 | 8.96751607e-7 |
| 50 | 0.000001793503214 |
| 100 | 0.000003587006428 |
| 1000 | 0.00003587006428 |
About these measurements
Area measures a surface in two dimensions.
The base reference used here is the square meter. One square foot is 0.09290304 base units; one square mile is 2,589,988.11 base units.
Important distinctions
Square a length factor to convert an area. Units with equal factors can have different conventional uses.
Precision
The converter uses stored conversion factors and floating-point arithmetic. Results display up to ten significant digits, switching to scientific notation for very small or large values. Keep the precision of your original measurement when reporting results.
Common questions
How do I convert ft² to mi²?
Multiply the quantity in ft² by 3.58700643e-8. You can also type the value into the converter above.
Can I reverse the conversion?
Yes. Use the swap button or open the square mile to square foot converter.
Reference
NIST Guide to the SI — conversion factors and prefix conventions. SI prefixes scale units by powers of ten; the dimension-specific notes above describe the assumptions used on this page.
