1 ft² = 3.5870 × 10^−8 mi² (square foot → square mile)
1 ft² = 3.5870 × 10^−8 mi²
1 square foot equals 3.5870 × 10^−8 square miles. To convert square feet to square miles, multiply the square foot value by 3.5870 × 10^−8. For quick reference: 1 ft² = 3.5870 × 10^−8 mi², 5 ft² = 1.7935 × 10^−7 mi², 10 ft² = 3.5870 × 10^−7 mi², 100 ft² = 3.5870 × 10^−6 mi².
Square miles = Square feet × 3.5870 × 10^−8Square feet to square miles divides by 27,878,400 (5,280² — the square-mile's exact definition in feet). Ten million square feet is 0.36 sq mi. Like the km² conversion, this is an aggregation tool: it appears when building-scale data (square footage of retail space, for example) needs to be expressed against the square-mile geography that US census and planning data use.
Start with your value in square feet.
Multiply the square foot value by 3.5870 × 10^−8. This is the exact conversion factor from square feet to square miles.
The product is your value in square miles. For example, 5 ft² × 3.5870 × 10^−8 = 1.7935 × 10^−7 mi².
The exact factor from square feet to square miles is 3.5870 × 10^−8.
Square miles = Square feet × 3.5870 × 10^−8
Fifty common reference values, hand-picked for skim utility. Use the calculator above for any value not listed.
| Square feet (ft²) | Square miles (mi²) |
|---|---|
| 0.1 ft² | 3.5870 × 10^−9 mi² |
| 0.25 ft² | 8.9675 × 10^−9 mi² |
| 0.5 ft² | 1.7935 × 10^−8 mi² |
| 1 ft² | 3.5870 × 10^−8 mi² |
| 2 ft² | 7.1740 × 10^−8 mi² |
| 3 ft² | 1.0761 × 10^−7 mi² |
| 4 ft² | 1.4348 × 10^−7 mi² |
| 5 ft² | 1.7935 × 10^−7 mi² |
| 6 ft² | 2.1522 × 10^−7 mi² |
| 7 ft² | 2.5109 × 10^−7 mi² |
| 8 ft² | 2.8696 × 10^−7 mi² |
| 9 ft² | 3.2283 × 10^−7 mi² |
| 10 ft² | 3.5870 × 10^−7 mi² |
| 12 ft² | 4.3044 × 10^−7 mi² |
| 15 ft² | 5.3805 × 10^−7 mi² |
| 20 ft² | 7.1740 × 10^−7 mi² |
| 25 ft² | 8.9675 × 10^−7 mi² |
| 30 ft² | 1.0761 × 10^−6 mi² |
| 40 ft² | 1.4348 × 10^−6 mi² |
| 50 ft² | 1.7935 × 10^−6 mi² |
| 60 ft² | 2.1522 × 10^−6 mi² |
| 70 ft² | 2.5109 × 10^−6 mi² |
| 75 ft² | 2.6903 × 10^−6 mi² |
| 80 ft² | 2.8696 × 10^−6 mi² |
| 90 ft² | 3.2283 × 10^−6 mi² |
| 100 ft² | 3.5870 × 10^−6 mi² |
| 120 ft² | 4.3044 × 10^−6 mi² |
| 150 ft² | 5.3805 × 10^−6 mi² |
| 200 ft² | 7.1740 × 10^−6 mi² |
| 250 ft² | 8.9675 × 10^−6 mi² |
| 300 ft² | 1.0761 × 10^−5 mi² |
| 400 ft² | 1.4348 × 10^−5 mi² |
| 500 ft² | 1.7935 × 10^−5 mi² |
| 600 ft² | 2.1522 × 10^−5 mi² |
| 750 ft² | 2.6903 × 10^−5 mi² |
| 800 ft² | 2.8696 × 10^−5 mi² |
| 1000 ft² | 3.5870 × 10^−5 mi² |
| 1200 ft² | 4.3044 × 10^−5 mi² |
| 1500 ft² | 5.3805 × 10^−5 mi² |
| 2000 ft² | 7.1740 × 10^−5 mi² |
| 2500 ft² | 8.9675 × 10^−5 mi² |
| 3000 ft² | 0.00010761 mi² |
| 4000 ft² | 0.00014348 mi² |
| 5000 ft² | 0.00017935 mi² |
| 7500 ft² | 0.00026903 mi² |
| 10000 ft² | 0.0003587 mi² |
| 20000 ft² | 0.0007174 mi² |
| 50000 ft² | 0.0017935 mi² |
| 100000 ft² | 0.003587 mi² |
| 1000000 ft² | 0.03587 mi² |
The median new US single-family home is around 2,200 sq ft. A standard two-car garage is 400–600 sq ft.
The square foot is the standard area unit for US and Canadian real estate, and remains common in UK property listings alongside square meters. One square foot is exactly 0.09290304 m² (derived from 1 ft = 0.3048 m squared). A typical US single-family home is 1,500–2,500 sq ft; a two-car garage is about 400–600 sq ft.
The square mile is the imperial unit for large land areas, standard in US geography and census data. One square mile is exactly 2.589988110336 km² (1.609344 km squared), or 640 acres — the basis of the US Public Land Survey System's square-mile 'sections'. Los Angeles covers about 469 square miles.