Km Squared to Acres: Quick Conversion

This calculator converts an area given in square kilometers (km²) to acres (ac) and also shows the result in square miles and square meters. Enter the area in square kilometers, and you get the equivalent in acres instantly, along with the conversion factor used. The standard conversion is 1 square kilometer = 247.105381 acres.

Formula

The formula to convert square kilometers to acres is:

Acres = Square Kilometers × 247.105381

Where:

• Square Kilometers (km²) is the area you start with.
• 247.105381 is the exact number of acres in one square kilometer, based on the international acre (4,046.8564224 m²).

Worked Example

Using the default value of 1 km²:

1. Start with 1 km².
2. Multiply by the conversion factor: 1 × 247.105381 = 247.105381 acres.
3. Rounded to two decimal places: 247.11 acres.

So 1 square kilometer equals 247.11 acres (rounded). For 5 km², multiply 5 × 247.105381 = 1,235.53 acres.

Why Convert Between km² and Acres?

Square kilometers are the standard metric unit for large land areas, used in most countries for geographic, agricultural, and planning purposes. Acres are the customary unit in the United States and the United Kingdom for real estate, farming, and land records. If you are comparing land sizes across countries, reading a deed, or buying property in a country that uses acres, you need to convert. Even within the US, some federal land records use hectares or square kilometers, while local parcel maps use acres.

How the Conversion Works

The acre is defined as 43,560 square feet, which equals 4,046.8564224 square meters. A square kilometer is 1,000,000 square meters. Dividing 1,000,000 by 4,046.8564224 gives 247.105381 acres. This is an exact international standard, not an approximation. The conversion factor is the same everywhere, so you can use it confidently for any area, from a small park to a whole county.

Common Mistakes and How to Avoid Them

• Confusing square kilometers with kilometers: A square kilometer is a unit of area, not length. You cannot convert km to acres directly; you need km².
• Using the wrong acre: The US survey acre (4,046.87261 m²) is slightly different from the international acre. For general use, the international acre is standard. The difference is tiny (about 0.016 m² per acre), but for very precise legal surveys, check which acre is used.
• Rounding too early: If you round the factor to 247, you get a small error. For large areas, use the full factor 247.105381.
• Forgetting to convert hectares: Some countries use hectares (1 ha = 10,000 m²). One hectare is about 2.471 acres. If you have a figure in hectares, convert to km² first (divide by 100) or use the hectare-to-acre factor directly.

Practical Examples of Sizes

To give you a sense of scale:

• A typical US city block (Manhattan) is about 0.006 km², which is roughly 1.5 acres.
• A large farm of 5 km² is about 1,235.5 acres – that’s a big operation.
• Central Park in New York City is about 3.41 km², which equals 843 acres (the official figure is 843 acres).
• A square kilometer is 100 hectares, so 1 km² is a 100-hectare block.

Limits of the Conversion

This conversion is purely mathematical and works for any area. The main limitation is the precision of the input. If you measure an area from a map or satellite, the accuracy depends on the measurement method, not the conversion. Also, for very large areas (like countries), the Earth’s curvature and map projections can cause discrepancies between a flat-map measurement and the true surface area. But for land parcels, the conversion is exact.

Frequently Asked Questions

How many acres are in 1 square kilometer?

Exactly 247.105381 acres. For quick mental math, you can remember it as about 247 acres per km².

What is the difference between a square kilometer and a kilometer squared?

They are the same thing. “Kilometer squared” is a common way to say square kilometer (km²). Both mean an area of 1,000 meters by 1,000 meters.

How do I convert acres to square kilometers?

Divide the number of acres by 247.105381. For example, 500 acres divided by 247.105381 gives 2.023 km².

Is an acre bigger than a square kilometer?

No. A square kilometer is much larger – about 247 times larger. One acre is roughly 0.004047 km².

Why are there two different acres?

The international acre (4,046.8564224 m²) is the modern standard. The US survey acre (4,046.87261 m²) was used before 1959 and is still used in some US land surveys. The difference is about 0.016 square meters, which is negligible for most purposes but can matter in large legal surveys.

Can I convert square miles to acres using this?

Yes, indirectly. One square mile is 640 acres. If you have square miles, multiply by 640 to get acres. Our calculator also shows square miles, so you can cross-check.

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in km2 | Area in square kilometers | km² | 1 | 0
out acres | Acres | ac | km2 * 247.105381 | 2
out sqmiles | Square miles | mi² | km2 * 0.386102 | 2
out sqmeters | Square meters | m² | km2 * 1000000 | 0