How do you convert square kilometers to acres?

To convert square kilometers (km²) to acres (ac), multiply the area in square kilometers by 247.10538 (acres = square kilometers × 247.10538).

What is 5 square kilometers in acres?

5 square kilometers (5 km²) is equal to 1,235.52691 acres (1,235.52691 ac).

Which is larger, 1 square kilometer (km²) or 1 acre (ac)?

One square kilometer (km²) is larger than one acre (ac). Specifically, 1 km² contains 247.10538 ac, whereas 1 ac is 0.00404685 km².

How do I convert back from acres (ac) to square kilometers (km²)?

To reverse the calculation from ac to km², multiply your acre value by the inverse factor 0.00404685 (or divide by 247.10538). You can also click the Swap button in the tool above to flip directions in one click.

Are there regional or standard differences when converting km² and ac?

International Foot vs. US Survey Foot: Under the 1959 International Yard and Pound Agreement, 1 international foot is defined as 0.3048 meters. Legacy US land deeds and State Plane Coordinate Systems prior to 2023 used the US Survey Foot (1200/3937 m ≈ 0.3048006096 m), a difference of 2 parts per million (about 0.01 ft per mile).

Square Kilometers to Acres Converter

Enter the area in square kilometers below to convert it to acres.

Acres to Square Kilometers (ac → km²)

Convert Square Kilometers to Acres

Enter a value in square kilometers (km²) to convert to acres (ac).

Value (km²)

From

Result

•

1,235.526907336acres

5 km² = 1,235.526907336 ac

Result updates automatically

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Equivalent Measurements Across UnitsFor 5 km²

Acres1,235.52691 ac

Suggested Conversions

Reference:NIST OWM (SI Units — Length & Area)

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Square Kilometer to Acre Conversion Table

Table showing various square kilometer measurements converted to acres. Click any preset value or arrow to load it into the converter.

Square Kilometers (km²)	Acres (ac)
1 km²	247.1053815 ac
2 km²	494.2107629 ac
2.5 km²	617.7634537 ac
5 km²	1,235.5269073 ac
10 km²	2,471.0538147 ac
15 km²	3,706.580722 ac
20 km²	4,942.1076293 ac
25 km²	6,177.6345367 ac
30 km²	7,413.161444 ac
50 km²	12,355.2690734 ac

How to Convert Square Kilometers to Acres

To convert square kilometers to acres, multiply the area by the following conversion ratio: 247.1053815 acres/square kilometer.

Since one square kilometer is equal to 247.1053815 acres, you can use this simple formula to convert:

acres = square kilometers × 247.1053815

The area in acres is equal to the area in square kilometers multiplied by 247.1053815.

For example, here's how to convert 5 square kilometers to acres using the formula above.

acres = (5 km² × 247.1053815) = 1,235.5269073 ac

How Many Acres Are in a Square Kilometer?

There are 247.1053815 acres in a square kilometer, which is why we use this value in the formula above.

1 km² = 247.1053815 ac|1 ac = 0.0040469 km²

Our square kilometer to acre calculator automatically converts your area measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.

Square Kilometers and acres are both units used to measure area. Keep reading to learn more about each unit.

What Is a Square Kilometer?

A square kilometer is a unit of area equal to 1,000,000 square meters (m²), the base unit for area. Equal to 1,000,000 square meters or 100 hectares. [1]

The square kilometer is classified as an International System of Units (SI) unit of area. Square Kilometers can be abbreviated as km²; for example, 1 square kilometer can be written as 1 km².

When working with square kilometers (km²) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.

In practice, square kilometers (km²) are widely used across large-scale industrial, bulk, and macro-level area specifications within International System of Units (SI) workflows, engineering documentation, and technical data sheets.

Learn more about square kilometers in our Area Converter.

What Is an Acre?

An acre is a unit of area equal to 4,046.8564224 square meters (m²), the base unit for area. Imperial & US Customary land unit equal to 43,560 square feet. [2]

The acre is classified as a US customary and imperial unit of area. Acres can be abbreviated as ac; for example, 1 acre can be written as 1 ac.

When working with acres (ac) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.

In practice, acres (ac) are widely used across large-scale industrial, bulk, and macro-level area specifications within US customary and imperial workflows, engineering documentation, and technical data sheets.

Learn more about acres in our Area Converter.

When converting area between square kilometers (km²) and acres (ac), keep full floating-point precision (1 km² = 247.1053815 ac; 1 ac = 0.0040469 km²) during intermediate calculations and round only the final acre figure to match your instrument tolerance.

More Square Kilometer & Acre Conversions

Need to calculate in the opposite direction? Use our acres to square kilometers calculator to switch your starting unit immediately. You can also explore related tools such as converting acres to square kilometers, converting hectares to acres, or converting square miles to acres.

Convert from Square Kilometers

Convert to Acres

Frequently Asked Questions

There are 247.10538 acres (ac) in 1 square kilometer (km²). Conversely, 1 acre (ac) is equal to 0.00404685 square kilometers (km²).

Area Converter

Quick Info

Direct Factor: 1 square kilometer (km²) equals 247.10538 acres (ac).
Inverse Factor: 1 acre (ac) equals 0.00404685 square kilometers (km²).
Formula: acres = square kilometers × 247.10538.
Standard Note: International Foot vs. US Survey Foot: Under the 1959 International Yard and Pound Agreement, 1 international foot is defined as 0.3048 meters. Legacy US land deeds and State Plane Coordinate Systems prior to 2023 used the US Survey Foot (1200/3937 m ≈ 0.3048006096 m), a difference of 2 parts per million (about 0.01 ft per mile).

Units Comparison

Square Kilometer (km²)

Equal to 1,000,000 square meters or 100 hectares.

Acre (ac)

Imperial & US Customary land unit equal to 43,560 square feet.

Square Meter (m²)

SI derived unit of surface area.

References

[1]NIST OWM · SI Units — Length & Area
Source
[2]NIST HB 44 · Acre, Hectare & Land Survey Tables
Source
[3]NIST SP 811 · NIST SP 811 App. B.9 (Area)
Source

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References

NIST · BIPM · ISO

[1]
NIST OWM (SI Units — Length & Area)·Area Metrology Standard — Square Kilometers (km²) to Acres (ac)
NIST OWM Standard
[2]
NIST HB 44 (Acre, Hectare & Land Survey Tables)·Unit Specifications: Square Kilometer (km²) & Acre (ac)
NIST HB 44 Specification
[3]
NIST SP 811 (NIST SP 811 App. B.9 (Area))·Conversion Factors & Mathematical Basis (km² to ac)
NIST SP 811 Reference

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