Acres to Square Kilometers Converter

1 acre is equal to 0.00404686 square kilometers, or 0.404686 ha.

Enter a value in the converter to get the result. This page explains the formula, works through examples and lists common values in a conversion table.

How to convert acres to square kilometers

Multiply the value in acres by 0.0040468564224 to get square kilometers.

km² = × 0.0040468564224
  1. 1Start with the value in acres: 1 ac.
  2. 2Apply the formula: × 0.0040468564224 = 0.0040468564224.
  3. 3Round to the precision you need: 0.00404686 km².

For a quick estimate without a calculator, divide by 247. For 1 ac that gives about 0.00405 km².

Examples

10 ac to km² × 0.0040468564224
= 0.0404686 km²50 ac to km² × 0.0040468564224
= 0.202343 km²250 ac to km² × 0.0040468564224
= 1.01171 km²

Acres to Square Kilometers conversion table

Acres (ac)Square Kilometers (km²)Hectares (ha)
1 ac0.00404686 km²0.404686 ha
5 ac0.0202343 km²2.02343 ha
10 ac0.0404686 km²4.04686 ha
20 ac0.0809371 km²8.09371 ha
25 ac0.101171 km²10.1171 ha
50 ac0.202343 km²20.2343 ha
75 ac0.303514 km²30.3514 ha
100 ac0.404686 km²40.4686 ha
150 ac0.607028 km²60.7028 ha
200 ac0.809371 km²80.9371 ha
500 ac2.02343 km²202.343 ha
1,000 ac4.04686 km²404.686 ha

1 acre in other units

The same value in every other unit of this category. Each row links to the full conversion.

UnitFormula1 ac equals
Acres to Square Millimetersmm² = × 4,046,856,422.44,046,856,422.4 mm²
Acres to Centimeterscm² = × 40,468,564.22440,468,564.22 cm²
Acres to Square Metersm² = × 4,046.85642244,046.86 m²
Acres to Hectaresha = × 0.404685642240.404686 ha
Acres to Square Kilometerskm² = × 0.00404685642240.00404686 km²
Acres to Square Inchesin² = × 6,272,6406,272,640 in²
Acres to Square Yardsyd² = × 4,8404,840 yd²
Acres to Square Feetft² = × 43,56043,560 ft²
Acres to Square Milesmi² = × 0.00156250.0015625 mi²

Square Kilometers to Acres

The reverse conversion uses the inverse formula. For example, 1 km² is 247.105 ac. Use the square kilometers to acres converter for other values.

ac = ÷ 0.0040468564224
1 km² to ac5 km² to ac10 km² to ac25 km² to ac50 km² to ac100 km² to ac500 km² to ac1,000 km² to ac

About the units

Acre (ac)

A unit of area in the imperial and US customary systems. 1 ac = 0.00404686 km².

Square Kilometer (km²)

A unit of area in the metric system. 1 km² = 247.105 ac.

Accuracy and rounding

The calculation uses exact decimal arithmetic, so the conversion itself adds no error. Results are rounded to six significant figures; the formula steps show more digits.

More acres to square kilometers conversions

2 ac to km²5 ac to km²10 ac to km²20 ac to km²25 ac to km²50 ac to km²75 ac to km²100 ac to km²150 ac to km²200 ac to km²250 ac to km²500 ac to km²1,000 ac to km²

FAQ

How many square kilometers are in one acre?

One acre is equal to 0.00404686 square kilometers.

How do I convert square kilometers back to acres?

Use the formula ac = ÷ 0.0040468564224. See the square kilometers to acres converter.