Square Kilometers to Acres
Convert square kilometers to acres instantly — one square kilometer is 247.105 acres.
| Square Kilometers | Acres |
|---|---|
| 1 km² | 247.105381 ac |
| 2 km² | 494.210763 ac |
| 3 km² | 741.316144 ac |
| 5 km² | 1235.526907 ac |
| 10 km² | 2471.053815 ac |
| 25 km² | 6177.634537 ac |
| 50 km² | 12355.269073 ac |
| 100 km² | 24710.538147 ac |
How to use
- Enter a value in the Square Kilometers field.
- The Acres figure appears immediately — no button to press.
- Typing in the Acres field converts back to Square Kilometers the same way.
- Use the reference table for the values that come up most often.
Square Kilometers to Acres formula
The factor from square kilometers to acres is 247.105381.
ac = km² × 247.105381
Why this factor: the square kilometer and the acre are both defined against the square meter, so dividing one definition by the other gives 247.105381 directly. Both definitions are set out in full below.
To go the other way, divide by 247.105381 — or use the Acres to Square Kilometers converter, which is the same calculation reversed.
Worked example
Take 1000 km² and multiply by the factor 247.105381: the result is 247105.381467 ac.
1000 km² × 247.105381 = 247105.381467 ac
The converter above does this for any value you type, in either direction.
What is a square kilometer?
A square kilometer is the area of a one-kilometer square — one million square meters.
Definition: Exactly 1×10⁶ square meters. Note it is the kilometer that is squared, not the prefix applied to a square meter.
Where it is used: City, national park and country areas, population density, and land cover statistics.
What is an acre?
An acre is the customary land area unit of the US and UK, historically a day's ploughing for one team of oxen.
Definition: One chain by one furlong — 43,560 square feet — which is exactly 4,046.8564224 square meters.
Where it is used: US and UK property and farmland, development parcels, and land sales.
Worth knowing: 640 acres make one square mile, the basis of the US Public Land Survey grid.
Square Kilometers vs Acres
The square kilometer is a metric unit while the acre is an imperial unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many acres are in a square kilometer?
One square kilometer equals 247.105381 acres.
What is the formula to convert square kilometers to acres?
Multiply the number of square kilometers by 247.105381. To reverse it, divide by 247.105381 instead.
How do I convert acres back to square kilometers?
Divide by 247.105381, which is the same as multiplying by 0.00404685642.
How many acres are in 10 square kilometers?
10 km² works out to 2471.053815 ac.
Is there anything to watch out for with acres?
640 acres make one square mile, the basis of the US Public Land Survey grid.
How is the square kilometer defined?
Exactly 1×10⁶ square meters. Note it is the kilometer that is squared, not the prefix applied to a square meter.