ac to mi² — convert acres to square miles
Exact 1 ÷ 640 = 0.0015625
4,046 square metres 8,564 square centimetres
1 acre in other units
| Square millimetres | 4,046,856,422.4 | mm² |
|---|---|---|
| Square centimetres | 40,468,564.22 | cm² |
| Square metres | 4,046.86 | m² |
| Ares | 40.468564 | a |
| Hectares | 0.40468564 | ha |
| Square kilometres | 0.004046856422 | km² |
| Square inches | 6,272,640 | in² |
| Square feet | 43,560 | ft² |
| Square yards | 4,840 | yd² |
| Square miles | 0.0015625 | mi² |
ac to mi² at a glance
| Acres | Square miles |
|---|---|
| 1 ac | 0.0015625 mi² |
| 2 ac | 0.003125 mi² |
| 3 ac | 0.0046875 mi² |
| 5 ac | 0.0078125 mi² |
| 10 ac | 0.015625 mi² |
| 20 ac | 0.03125 mi² |
| 25 ac | 0.0390625 mi² |
| 50 ac | 0.078125 mi² |
| 100 ac | 0.15625 mi² |
| 250 ac | 0.390625 mi² |
| 500 ac | 0.78125 mi² |
| 1,000 ac | 1.5625 mi² |
How to convert acres to square miles
Multiply by 0.0015625 — one acre is 0.0015625 square miles. That factor is exact: it comes from the definition of the units rather than from a measurement, so it will not change and does not need rounding.
Working 1 ÷ 640 = 0.0015625
Questions
How many square miles are in a acre?
One acre is 0.0015625 square miles. This figure is exact — it comes from the definition of the unit, not a measurement.
What is 1 acre in square miles?
1 acre is 0.0015625 square miles. The working is 1 ÷ 640 = 0.0015625.
How big is an acre, really?
About 4,047 square metres, or roughly 70 by 58 metres if it were square — though it rarely is. The traditional definition was one chain by one furlong, the strip a team of oxen could plough in a day, which is why it is a long thin shape rather than a round number.
How many acres in a hectare?
A hectare is about 2.47 acres. The hectare is the tidier unit: it is exactly 10,000 square metres, or a square 100 metres on each side. Most of the world quotes land in hectares and only the English-speaking countries still lean on the acre.
Why isn't a square foot 12 square inches?
Because area scales with the square of length. A foot is 12 inches, so a square foot is 12 × 12 = 144 square inches. The same catch doubles again for volume, where a cubic foot is 1,728 cubic inches.
What area is a football pitch?
There is no single answer, which is why it is a poor unit despite being a popular one. FIFA allows pitches between roughly 4,050 and 10,800 square metres, so "the size of a football pitch" can vary by a factor of more than two.