Convert Acres to Square kilometres
1 acre is 0.004047 km². One acre is exactly 0.0040468564224 square kilometres.
One acre is 0.0040468564 square kilometres. To convert acres to square kilometres, multiply by 0.0040468564; to go the other way, divide by 0.0040468564 or multiply by 247.10538. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST Office of Weights and Measures. Exactly 43,560 square feet — historically the land one team of oxen could plough in a day.
Factor checked against the defining standard · How we check
- Acres × 0.0040468564
1 * 0.00404690.004 km²
1 acre in every area unit
| Unit | Value | Exact factor |
|---|---|---|
| square inches | 6,272,640 sq in | × 6,272,640 |
| square feet | 43,560 sq ft | × 43,560 |
| square yards | 4,840 sq yd | × 4,840 |
| acres (as entered) | 1 ac | — |
| square meters | 4,046.856422 m² | × 4,046.8564224 |
| square millimetres | 4,046,856,422 mm² | × 4,046,856,422.4 |
| square centimetres | 40,468,564.22 cm² | × 40,468,564.224 |
| square kilometres | 0.004046856422 km² | × 0.0040468564224 |
| square miles | 0.0015625 mi² | × 0.0015625 |
| hectares | 0.4046856422 ha | × 0.40468564224 |
Factors are entered by hand from NIST Office of Weights and Measures rather than derived from a units library, so the ones that terminate are exact rather than rounded.
The same converter answers this pair however it is written: ac to sqkm is how the symbols are typed on a keyboard with no superscript on it.
How do you convert acres to square kilometres? The converter and the working
- 1.Take the measurement in acres.
- 2.Multiply by 0.0040468564 — that is how many square kilometres fit in one acre.
- 3.To go back the other way, divide by 0.0040468564, or multiply by 247.10538.
Worked example: 25 acres to square kilometres
- Formula
- ac × 0.0040468564 = km²
- Arithmetic
- 25 × 0.0040468564 = 0.1 km²
- Answer
- 25 ac = 0.1 km²
The factor is rounded for display; the figure above is computed from the full value.
Acres to square kilometres conversion table
| Acres | Square kilometres |
|---|---|
| 1 ac | 0.004047 km² |
| 2 ac | 0.01 km² |
| 3 ac | 0.01 km² |
| 4 ac | 0.02 km² |
| 5 ac | 0.02 km² |
| 6 ac | 0.02 km² |
| 7 ac | 0.03 km² |
| 8 ac | 0.03 km² |
| 9 ac | 0.04 km² |
| 10 ac | 0.04 km² |
| 12 ac | 0.05 km² |
| 15 ac | 0.06 km² |
| 20 ac | 0.08 km² |
| 25 ac | 0.1 km² |
| 50 ac | 0.2 km² |
| 100 ac | 0.4 km² |
| 200 ac | 0.81 km² |
| 300 ac | 1.21 km² |
| 500 ac | 2.02 km² |
| 1000 ac | 4.05 km² |
| 2000 ac | 8.09 km² |
| 5000 ac | 20.23 km² |
| 10000 ac | 40.47 km² |
What is an acre?
Exactly 43,560 square feet — historically the land one team of oxen could plough in a day.
What is a square kilometre?
A million square metres, or 100 hectares. The unit land area and population density are published in everywhere except the US.
How many square kilometres are in an acre?
One acre is 0.0040468564 square kilometres. Going the other way, one square kilometre is 247.10538 acres. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every area unit here
The whole group — 10 units with their symbols and the size of each one in square meters — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to an acre.
Cite this page
- APA
- Rule Calculator. (2026). Convert Acres to square kilometres. Rule Calculator. https://rulecalculators.com/convert/acre-to-square-kilometer
- MLA
- "Convert Acres to square kilometres." Rule Calculator, August 16, 2026, https://rulecalculators.com/convert/acre-to-square-kilometer.
- Chicago
- Rule Calculator. "Convert Acres to square kilometres." Rule Calculator. Last reviewed August 16, 2026. https://rulecalculators.com/convert/acre-to-square-kilometer.
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Questions people actually ask
- How many square kilometres are in an acre?
- 0.0040468564. A million square metres, or 100 hectares. The unit land area and population density are published in everywhere except the US.
- How do I convert square kilometres back to acres?
- Divide by 0.0040468564, or multiply by 247.10538 — they are the same operation.
Other area conversions
Square kilometres to acres — the same conversion the other way.