Convert acre to hectare.

Convert acre (acre) to hectare (ha). This is a fixed-ratio conversion — multiply the input by the factor below.

Formula

ha = acre × 0.404686

Reference values

Things to watch for

• Area scales as the square of length: doubling each side multiplies area by 4.
• 1 acre = 4046.86 m² = 43,560 ft² (exact). Originally the area one ox could plow in a day.
• 1 hectare = 10,000 m² (a 100 × 100 m square). Commonly used in agriculture and real estate outside the US.

What is a acre?

One acre equals exactly 43,560 square feet or about 4,046.86 square meters — historically the area a yoke of oxen could plow in a day. Land area in the US, UK, and many Commonwealth countries.

What is a hectare?

One hectare equals exactly 10,000 square meters or about 2.471 acres. Land area in metric countries, especially for agricultural and forestry use.

Real-world examples of acre

If the unit feels abstract, comparing it to known objects often helps. 1 acre is roughly the size of an American football field (without end zones); 640 acres is one square mile.

How to convert acre to hectare

To convert a value from acre (acre) to hectare (ha), apply the conversion factor shown in the formula above. The calculation is the same whether you do it by hand, in a spreadsheet, or with the live converter on this page.

Steps:

1. Take your input value in acre.
2. Apply the formula ha = acre × 0.404686.
3. The result is your value in ha.

For repeated calculations, save the formula in a spreadsheet or use the live converter at the top of this page — it handles the math automatically and displays the result as you type.

Frequently asked questions

How do I convert acre to ha?

Apply the formula acre → ha shown above, or just type your value into the converter at the top of this page. The result updates instantly.

Which is bigger, acre or ha?

This depends on the conversion ratio in the formula. If the factor multiplied by your value gives a larger number, then ha is the smaller unit (so it takes more of them to express the same quantity). If the result is smaller, then ha is the larger unit.

When would I use acre versus ha?

Both units measure area, so the choice depends on context. Acre is typically used for real estate, land measurement, and floor planning; hectare similarly. Most professional fields standardize on one or the other based on regional conventions or technical tradition.

How precise is this acre to ha conversion?

The conversion factor shown is the internationally defined exact value (or the best-published approximation if the relationship is irrational, like degrees-to-radians). The live converter on this page uses double-precision floating-point math, accurate to about 15 significant digits — far beyond any practical engineering need.

Is the conversion ratio exact, or an approximation?

Most unit conversions between SI metric units, and between SI and US customary units, have been formally defined as exact values since the 1959 international yard-pound agreement and subsequent SI redefinitions. Exceptions are unit pairs that involve irrational numbers (radians, e.g.) or empirical conversions (like food calories, which depend on temperature). When in doubt, consult the formula at the top of this page.

Related conversions

See also