Square miles to acres converter
Acres (ac)
1 square mile = 640 acres
How to convert square miles to acres
ac = mi² × 640
Multiply the number of square miles by 640 to get acres. Going the other way, divide by 640 (or multiply by 0.0015625).
One square mile is exactly defined as 640 acres (to 12 significant figures), and one acre is 0.0015625 square miles.
Worked examples
- Convert 5 square miles: 5 × 640 = 3,200 3,200 acres.
- Convert 12.5 square miles: 12.5 × 640 = 8,000 8,000 acres.
- Convert 250 square miles: 250 × 640 = 160,000 160,000 acres.
Quick-reference table
| mi² | ac |
|---|---|
| 1 | 640 |
| 2 | 1,280 |
| 3 | 1,920 |
| 5 | 3,200 |
| 10 | 6,400 |
| 15 | 9,600 |
| 20 | 12,800 |
| 25 | 16,000 |
| 50 | 32,000 |
| 75 | 48,000 |
| 100 | 64,000 |
| 1,000 | 640,000 |
| ac | mi² |
|---|---|
| 1 | 0.0015625 |
| 2 | 0.003125 |
| 3 | 0.0046875 |
| 5 | 0.0078125 |
| 10 | 0.015625 |
| 15 | 0.0234375 |
| 20 | 0.03125 |
| 25 | 0.0390625 |
| 50 | 0.078125 |
| 75 | 0.1171875 |
| 100 | 0.15625 |
| 1,000 | 1.5625 |
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Frequently asked questions
How many acres are in 1 square mile?
1 square mile equals 640 acres.
What is the formula to convert square miles to acres?
Use ac = mi² × 640. Multiply the number of square miles by 640 to get acres. Going the other way, divide by 640 (or multiply by 0.0015625).
What is 100 square miles in acres?
100 square miles is 64,000 acres.