Acres to Hectares Converter

How to use the acres to hectares converter

1. Enter a number in the Acres field to convert to hectares, or in the Hectares field to convert to acres.
2. The result updates automatically as you type.
3. Use the output rows to read the converted value, square meters, and square feet equivalents.

How the acres to hectares conversion works

The international acre is defined as exactly 4,046.8564224 square meters. A hectare is defined as exactly 10,000 square meters. Dividing these gives the exact conversion factor:

1 acre = 4,046.8564224 / 10,000 = 0.40468564224 hectares

To go the other direction, divide 10,000 by 4,046.8564224:

1 hectare = 10,000 / 4,046.8564224 = 2.47105381467... acres

For example, converting 40 acres to hectares: 40 x 0.40468564224 = 16.1874256896 hectares. The calculator rounds this to six decimal places for readability while preserving full precision internally.

Common land area conversions

This table shows frequently used values when converting acres to hectares and vice versa. These are handy references for real estate, farming, and land surveying.

When to use acres versus hectares

Acres are the standard unit of land area in the United States, the United Kingdom (for agricultural and forestry purposes), and several other countries that historically used the imperial system. One acre was originally defined as the amount of land a yoke of oxen could plow in one day, standardized later as an area of one chain by one furlong (66 by 660 feet).

Hectares are part of the metric system and are used in most of the world, including all of continental Europe, Australia, Canada, and South America. The hectare is not technically an SI base unit but is accepted for use with SI. It is preferred in agriculture, forestry, urban planning, and scientific research because it relates cleanly to square meters and square kilometers (100 hectares = 1 square kilometer).

If you also need to convert to or from square feet, the square meters to square feet converter handles that step.

Relationship to other area units

Land area is often discussed in multiple units depending on context. Here is how the acre and hectare relate to other common measures:

• Square meters: 1 acre = 4,046.8564224 m²; 1 hectare = 10,000 m².
• Square kilometers: 1 km² = 100 hectares = 247.105381 acres.
• Square miles: 1 square mile = 640 acres = 258.998811 hectares.
• Square feet: 1 acre = 43,560 ft²; 1 hectare = 107,639.104 ft².

For linear conversions related to property boundaries, tools like cm to feet or mm to inches can help translate fence lengths or lot dimensions.

Precision and rounding notes

The conversion factor from acres to hectares (0.40468564224) is exact by definition under the international yard and pound agreement of 1959, which fixed the yard at exactly 0.9144 meters. Because the acre is defined as 4,840 square yards, its metric equivalent is a terminating decimal.

The reverse factor (hectares to acres) produces a repeating decimal. This calculator uses sufficient internal precision to avoid floating point drift, then rounds the displayed result to six decimal places. For legal surveys or cadastral work, always verify against local standards, as some jurisdictions use historical definitions of the acre that differ slightly from the international standard.

Worked examples

Each result below was produced by the same code the tool runs, so you can check your own numbers against them.