Acres to hectares

Multiply acres by 0.404686 to get hectares.

1 ac = 0.404686 haNIST HB 44 · BIPM SI

Convert

8.0937ha

20 ac = 8.0937 ha

How to convert acres to hectares

The hectare is exactly 10 000 m² — the metric unit for land area. The acre is exactly 43 560 square feet (4046.8564224 m²).

Worked example — 20 ac: 20 × 0.404686 = 8.0937 ha.

Acres to hectares table

Common conversions. The reverse table is on hectares to acres.
Acres	Hectares
1 ac	0.404686 ha
2 ac	0.809371 ha
5 ac	2.0234 ha
10 ac	4.0469 ha
20 ac	8.0937 ha
50 ac	20.2343 ha
100 ac	40.4686 ha
250 ac	101.1714 ha
640 ac	258.9988 ha

Reverse and related

hectares → acresreverse conversion ac → ft²1 ac = 43,560 ft² ac → m²1 ac = 4,046.8564 m² ft² → ac1 ft² = 0.0000229568 ac m² → ac1 m² = 0.000247105 ac ha → m²1 ha = 10,000 m² ha → ft²1 ha = 107,639.1042 ft²

About acres and hectares

Acre (ac)

1 ac = 0.404686 ha

Definition. Exactly 43 560 square feet (4046.8564224 m²)

History and origin

The acre began as the area a yoke of oxen could plough in a day, later fixed as 43 560 square feet, or one furlong by one chain. It equals about 4047 square metres.

Current use

Acres are the customary measure for land, farm plots and larger properties in the United States and United Kingdom.

Source: NIST Handbook 44, Appendix C (area); 1959 yard-and-pound agreement

Hectare (ha)

1 ha = 2.4711 ac

Definition. Exactly 10 000 m² — the metric unit for land area

History and origin

The hectare was introduced with the metric system as a practical unit for land, equal to 10 000 square metres, or a square 100 metres on each side. Its name joins hecto, for a hundred, with the are of 100 square metres.

Current use

Hectares measure farmland and land area throughout the metric world.

Source: BIPM SI Brochure (2019)

Where people use this

Acres: land and farm plots, US real estate. Hectares: farmland, land area outside the US. 1 acre is about 0.405 hectares.

How we know this is right

The factor is fixed by the standards that define the units, not chosen — so it is exact, not a measurement:

1 ha = 2.471053815 ac, so 1 ac = 1 ÷ 2.471053815 = 0.404686 ha.

Every value is carried to full double precision; the display is rounded.

Sources: BIPM SI Brochure (2019); NIST Handbook 44, Appendix C (area); 1959 yard-and-pound agreement.

Questions people ask

How many hectares in an acre?

One acre is about 0.405 hectares.

How many hectares is 10 acres?

10 acres is about 4.05 hectares.

How many acres make a hectare?

It takes about 2.47 acres to make one hectare.

All acre conversions

Acres to square feet1 ac = 43,560 ft² Acres to square metres1 ac = 4,046.8564 m² Hectares to acres1 ha = 2.4711 ac Square feet to acres1 ft² = 0.0000229568 ac Square metres to acres1 m² = 0.000247105 ac Acres to square miles1 ac = 0.0015625 mi² Square miles to acres1 mi² = 640 ac