How to convert acres to square kilometers
Acres and Square Kilometers both measure area, so converting is a single multiplication. One ac equals 0.004047 km², so you multiply your acres value by 0.004047.
Formula: square kilometers = acres × 0.004047. For example, 10 ac = 0.040469 km².
Acres to Square Kilometers conversion table
| Acres (ac) | Square Kilometers (km²) |
|---|---|
| 1 | 0.004047 |
| 2 | 0.008094 |
| 5 | 0.020234 |
| 10 | 0.040469 |
| 25 | 0.101171 |
| 50 | 0.202343 |
| 100 | 0.404686 |
| 1,000 | 4.046856 |
Acres and Square Kilometers explained
Acres (ac): About 4,047 m², a traditional unit for land and farming.
Square Kilometers (km²): One million square metres, used for regions and countries.
When you'd convert acres to square kilometers
You'll convert acres to square kilometers whenever a measurement is given in one unit but you need it in the other — comparing acres and square kilometers figures across regions, following a recipe or spec, or double-checking a number. Because 1 ac is exactly 0.004047 km², the result is precise every time.
Frequently asked questions
How many square kilometers are in a acre?
One ac equals 0.004047 km². Multiply your acres figure by 0.004047 to get square kilometers.
What is the formula to convert acres to square kilometers?
square kilometers = acres × 0.004047. The factor 0.004047 is exact.
What is 2 acres in square kilometers?
2 ac = 0.008094 km². You can enter any value in the converter above to get an instant result.
Is this Acres to Square Kilometers converter accurate?
Yes. It uses the standard conversion factor (1 ac = 0.004047 km²) defined by BIPM — SI Brochure (derived units), so results are exact to several decimal places.