Convert acres to square miles
Acre (ac) to square mile (mi²). One acre equals 0.001563 square miles.
Formula
Acre to square mile conversion table
| Acres | Square miles | Square miles | Acres |
|---|---|---|---|
| 1 ac | 0.001563 mi² | 1 mi² | 640 ac |
| 2 ac | 0.003125 mi² | 2 mi² | 1280 ac |
| 3 ac | 0.004687 mi² | 3 mi² | 1920 ac |
| 5 ac | 0.007813 mi² | 5 mi² | 3200 ac |
| 10 ac | 0.015625 mi² | 10 mi² | 6400 ac |
| 20 ac | 0.03125 mi² | 20 mi² | 12800 ac |
| 50 ac | 0.078125 mi² | 50 mi² | 32000 ac |
| 100 ac | 0.15625 mi² | 100 mi² | 64000 ac |
| 500 ac | 0.78125 mi² | 500 mi² | 320000 ac |
| 1000 ac | 1.5625 mi² | 1000 mi² | 640000 ac |
To convert acres to square miles, divide the number of acres by 640. One acre equals 0.001563 square miles, and one square mile equals 640 acres, so the relationship is fixed and exact. As a worked example, 10 ac comes to 0.015625 mi². Enter your own figure in the converter above to get an instant answer, or use the swap button to flip the direction. This is a area conversion, and like every tool on UnitGlide it runs locally in your browser with no account or upload required. The table further down shows a range of common acre values already worked out in square miles, plus the reverse square mile to acre direction, which is handy for quick reference or double-checking a result by hand.
Frequently asked questions
How many square miles are in an acre?
One acre equals 0.001563 square miles. The ratio is constant, so you can multiply any number of acres by 0.001563 to get square miles.
What is the formula to convert acres to square miles?
Use square miles = acres ÷ 640. UnitGlide applies this exact formula for every value, so results stay accurate across the whole range.
How do I convert square miles back to acres?
Go the other way by using one square mile equals 640 acres. You can also press the swap button in the converter above to flip the direction in one click.
Is this acre to square mile converter accurate?
Yes. It uses internationally defined SI conversion factors, as maintained by the BIPM, and all math runs in your browser so nothing is rounded away on a server. For everyday use the displayed precision is more than enough.