Convert Acres to Square Kilometers
Convert Acres to Square Kilometers instantly. 1 Acre (ac) equals 0.004047 Square Kilometers (km²).
Acres to Square Kilometers conversion table
| Acres (ac) | Square Kilometers (km²) |
|---|---|
| 1 ac | 0.004047 km² |
| 2 ac | 0.008094 km² |
| 3 ac | 0.01214 km² |
| 5 ac | 0.02023 km² |
| 10 ac | 0.04047 km² |
| 20 ac | 0.08094 km² |
| 50 ac | 0.2023 km² |
| 100 ac | 0.4047 km² |
| 500 ac | 2.0234 km² |
| 1,000 ac | 4.0469 km² |
1 Acre = 0.004047 Square Kilometers · multiply Acres by 0.004047
About converting Acres to Square Kilometers
Acres (ac) and Square Kilometers (km²) are both units of area, so converting between them is a single multiplication: multiply your Acres figure by 0.004047. Ten Acres comes to 0.04047 Square Kilometers, and a hundred works out at 0.4047 Square Kilometers.
Rule of thumb: going from Acres to Square Kilometers divides, so the figure always shrinks — it takes about 247.1054 Acres to make a single Square Kilometer. If your answer came out bigger, you have the conversion the wrong way round.
What is an Acre?
The acre is the awkward number in the system, and the reason is that it was never a piece of geometry: it was the area a man with a single ox could plough in a day. That gave it a shape as well as a size — one furlong long by one chain wide, the furlong being the length of the furrow before the team was turned around. Formalised as 4,840 square yards, it never rounded off to anything tidy, and nobody minded, because it described a day’s work. It is still the standard unit for land in the US and for farmland and property in the UK and India.
What is a Square Kilometer?
A square kilometer is the area of a square one kilometer on a side, and it is how the world reports anything from the size of a town upward: city footprints, lakes, national parks, forest lost to fire, the areas of countries. Its classic trap is that the prefix is squared along with the unit — both sides of the square grow by a thousand, so the area grows by that factor twice over, and people who expect a simple thousand-fold jump land three orders of magnitude out. The same squaring is why a map at twice the scale covers four times the ground.
To put both in perspective: a football pitch is a bit over an acre, while Central Park in New York is about 3.4 square kilometers.
The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Square Kilometers to Acres converter, or browse all Area converters.
Frequently asked questions
How many Square Kilometers are in one Acre?
There are 0.004047 Square Kilometers in one Acre.
How do I convert Acres to Square Kilometers?
Multiply the number of Acres by 0.004047. For example, 10 Acres = 0.04047 Square Kilometers.
What is 100 Acres in Square Kilometers?
100 Acres is equal to 0.4047 Square Kilometers.
How do I convert Square Kilometers to Acres?
Multiply the Square Kilometers value by 247.1054 (or divide by 0.004047).
Is this Acres to Square Kilometers conversion exact?
The definition is exact — Acres and Square Kilometers are both fixed against the same base by international agreement — but the decimal shown here is rounded for readability, because the true ratio does not terminate. For engineering or scientific work, carry more decimal places than this page displays.
What is an Acre?
The acre is the awkward number in the system, and the reason is that it was never a piece of geometry: it was the area a man with a single ox could plough in a day. That gave it a shape as well as a size — one furlong long by one chain wide, the furlong being the length of the furrow before the team was turned around. Formalised as 4,840 square yards, it never rounded off to anything tidy, and nobody minded, because it described a day’s work. It is still the standard unit for land in the US and for farmland and property in the UK and India.
What is a Square Kilometer?
A square kilometer is the area of a square one kilometer on a side, and it is how the world reports anything from the size of a town upward: city footprints, lakes, national parks, forest lost to fire, the areas of countries. Its classic trap is that the prefix is squared along with the unit — both sides of the square grow by a thousand, so the area grows by that factor twice over, and people who expect a simple thousand-fold jump land three orders of magnitude out. The same squaring is why a map at twice the scale covers four times the ground.