Square feet to square miles
square miles = square feet × 3.587006e-8
Reverse: square miles to square feet
How to convert square feet to square miles
One square foot is 3.587006e-8 square miles, so multiply the number of square feet by 3.587006e-8. For example, 20 square feet is 20 × 3.587006e-8 = 7.174013e-7 square miles. To go back, divide by the same number, or multiply by 27,878,400.
Quick estimate
Multiplying by about 4e-8 gets within 11.5% of the exact answer, which is enough to check that a result makes sense.
Where it comes up
Area conversions come up when buying flooring, paint or turf, comparing house and flat sizes, and measuring land and gardens.
| square feet | square miles |
|---|---|
| 1 ft2 | 3.587006e-8 mi2 |
| 2 ft2 | 7.174013e-8 mi2 |
| 3 ft2 | 1.076102e-7 mi2 |
| 4 ft2 | 1.434803e-7 mi2 |
| 5 ft2 | 1.793503e-7 mi2 |
| 6 ft2 | 2.152204e-7 mi2 |
| 7 ft2 | 2.510904e-7 mi2 |
| 8 ft2 | 2.869605e-7 mi2 |
| 9 ft2 | 3.228306e-7 mi2 |
| 10 ft2 | 3.587006e-7 mi2 |
| 11 ft2 | 3.945707e-7 mi2 |
| 12 ft2 | 4.304408e-7 mi2 |
| 13 ft2 | 4.663108e-7 mi2 |
| 14 ft2 | 5.021809e-7 mi2 |
| 15 ft2 | 5.38051e-7 mi2 |
| 16 ft2 | 5.73921e-7 mi2 |
| 17 ft2 | 6.097911e-7 mi2 |
| 18 ft2 | 6.456612e-7 mi2 |
| 19 ft2 | 6.815312e-7 mi2 |
| 20 ft2 | 7.174013e-7 mi2 |
| 25 ft2 | 8.967516e-7 mi2 |
| 30 ft2 | 0.00000108 mi2 |
| 40 ft2 | 0.00000143 mi2 |
| 50 ft2 | 0.00000179 mi2 |
| 60 ft2 | 0.00000215 mi2 |
| 70 ft2 | 0.00000251 mi2 |
| 75 ft2 | 0.00000269 mi2 |
| 80 ft2 | 0.00000287 mi2 |
| 90 ft2 | 0.00000323 mi2 |
| 100 ft2 | 0.00000359 mi2 |
| 120 ft2 | 0.0000043 mi2 |
| 150 ft2 | 0.00000538 mi2 |
| 200 ft2 | 0.00000717 mi2 |
| 250 ft2 | 0.00000897 mi2 |
| 300 ft2 | 0.00001076 mi2 |
| 400 ft2 | 0.00001435 mi2 |
| 500 ft2 | 0.00001794 mi2 |
| 750 ft2 | 0.0000269 mi2 |
| 1,000 ft2 | 0.00003587 mi2 |
| 1,500 ft2 | 0.00005381 mi2 |
| 2,000 ft2 | 0.00007174 mi2 |
| 5,000 ft2 | 0.00017935 mi2 |
| 10,000 ft2 | 0.0003587 mi2 |
Questions
How many square miles are in a square foot?
3.587006e-8 square miles.
How do I convert square feet to square miles in a spreadsheet?
Put the value in A1 and type =A1*3.587006e-8, then fill the formula down the column.
Are the values in the table exact?
They are calculated from the exact definitions of the units and rounded only for display. Open any row for the full working.