Convert square miles to acres
1 mi² = 640 ac — exactly. Both units are defined against the SI, so this factor is a fraction, not an approximation.
640ac
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1 mi² = 640 ac
Show this value in all 25 area units
- Square kilometers km² 2.589 988 110 34
- Square hectometers hm² 258.998 811 034
- Square decameters dam² 25 899.881 103 4
- Square meters m² 2 589 988.110 34
- Square decimeters dm² 258 998 811.034
- Square centimeters cm² 25 899 881 103.4
- Square millimeters mm² 2 589 988 110 340
- Square micrometers µm² 2.58998811034e+18
- Square nanometers nm² 2.58998811034e+24
- Hectares ha 258.998 811 034
- Ares a 25 899.881 103 4
- Decares daa 2589.988 110 34
- Square inches in² 4 014 489 600
- Square feet ft² 27 878 400
- Square yards yd² 3 097 600
- Square miles mi² 1
- Acres ac 640
- Roods ro 2560
- Square rods rd² 102 400
- Sections section 1
- Townships twp 0.027 777 777 777 8
- Roofing squares sq 278 784
- Circular mils cmil 5 111 406 910 650 000
- Barns b 2.58998811034e+34
- Tsubos 坪 783 471.403 377
Every row is Square mile (mi²) converted through the square meter, in exact rational arithmetic.
How to convert square miles to acres
Multiply the number of square miles by 640 to get acres.
The exact factor is 640 .
Acre: Exactly 4840 square yards — historically a day of ploughing.
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 |
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 |
Frequently asked
How many acres are in a square mile?
One square mile equals 640 acres (mi² → ac). That figure is exact, not rounded.
How do you convert square miles to acres?
Multiply the number of square miles by 640 to get acres.
What is 1 ac in square miles?
One acre is 0.0015625 square miles.
What is 10 mi² in ac?
10 mi² = 6400 ac.
What exactly is a acre?
Exactly 4840 square yards — historically a day of ploughing.