Convert acres to square miles
1 ac = 0.0015625 mi² — exactly. Both units are defined against the SI, so this factor is a fraction, not an approximation.
0.001 562 5mi²
As a fraction: 1/640
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1 ac = 0.0015625 mi²
Show this value in all 25 area units
- Square kilometers km² 0.004 046 856 422 4
- Square hectometers hm² 0.404 685 642 24
- Square decameters dam² 40.468 564 224
- Square meters m² 4046.856 422 4
- Square decimeters dm² 404 685.642 24
- Square centimeters cm² 40 468 564.224
- Square millimeters mm² 4 046 856 422.4
- Square micrometers µm² 4 046 856 422 400 000
- Square nanometers nm² 4.0468564224e+21
- Hectares ha 0.404 685 642 24
- Ares a 40.468 564 224
- Decares daa 4.046 856 422 4
- Square inches in² 6 272 640
- Square feet ft² 43 560
- Square yards yd² 4840
- Square miles mi² 0.001 562 5
- Acres ac 1
- Roods ro 4
- Square rods rd² 160
- Sections section 0.001 562 5
- Townships twp 0.000 043 402 777 777 8
- Roofing squares sq 435.6
- Circular mils cmil 7 986 573 297 890
- Barns b 4.0468564224e+31
- Tsubos 坪 1224.174 067 78
Every row is Acre (ac) converted through the square meter, in exact rational arithmetic.
How to convert acres to square miles
Multiply the number of acres by 0.0015625 to get square miles.
The exact factor is 0.0015625 — as a fraction, 1/640.
Acre: Exactly 4840 square yards — historically a day of ploughing.
Acre to Square mile conversion table
| Acres (ac) | Square miles (mi²) |
|---|---|
| 1 ac | 0.001 562 5 |
| 2 ac | 0.003 125 |
| 3 ac | 0.004 687 5 |
| 5 ac | 0.007 812 5 |
| 10 ac | 0.015 625 |
| 20 ac | 0.031 25 |
| 25 ac | 0.039 062 5 |
| 50 ac | 0.078 125 |
| 100 ac | 0.156 25 |
| 250 ac | 0.390 625 |
| 500 ac | 0.781 25 |
| 1000 ac | 1.5625 |
Square mile to Acre conversion table
| Square miles (mi²) | Acres (ac) |
|---|---|
| 1 mi² | 640 |
| 2 mi² | 1280 |
| 3 mi² | 1920 |
| 5 mi² | 3200 |
| 10 mi² | 6400 |
| 20 mi² | 12 800 |
| 25 mi² | 16 000 |
| 50 mi² | 32 000 |
| 100 mi² | 64 000 |
| 250 mi² | 160 000 |
| 500 mi² | 320 000 |
| 1000 mi² | 640 000 |
Frequently asked
How many square miles are in a acre?
One acre equals 0.0015625 square miles (ac → mi²). That figure is exact, not rounded.
How do you convert acres to square miles?
Multiply the number of acres by 0.0015625 to get square miles.
What is 1 mi² in acres?
One square mile is 640 acres.
What is 10 ac in mi²?
10 ac = 0.015 625 mi².
What exactly is a acre?
Exactly 4840 square yards — historically a day of ploughing.