ac to km² — convert acres to square kilometres
Exact 1 ÷ 247.105381 = 0.004046856422
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 km² at a glance
| Acres | Square kilometres |
|---|---|
| 1 ac | 0.004046856422 km² |
| 2 ac | 0.008093712845 km² |
| 3 ac | 0.01214057 km² |
| 5 ac | 0.02023428 km² |
| 10 ac | 0.04046856 km² |
| 20 ac | 0.08093713 km² |
| 25 ac | 0.10117141 km² |
| 50 ac | 0.20234282 km² |
| 100 ac | 0.40468564 km² |
| 250 ac | 1.011714 km² |
| 500 ac | 2.023428 km² |
| 1,000 ac | 4.046856 km² |
How to convert acres to square kilometres
Multiply by 0.004046856422 — one acre is 0.004046856422 square kilometres. 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 ÷ 247.105381 = 0.004046856422
What these units are
The acre and the square kilometre are covered in the area unit guide, along with every other unit on this page.
Questions
How many square kilometres are in a acre?
One acre is 0.004046856422 square kilometres. This figure is exact — it comes from the definition of the unit, not a measurement.
What is 1 acre in square kilometres?
1 acre is 0.004046856422 square kilometres. The working is 1 ÷ 247.105381 = 0.004046856422.
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.