acres to hectares converter

How to convert acres to hectares

An international acre is exactly 4046.8564224 square metres. A hectare is exactly 10,000 square metres, a square 100 metres on a side. The ratio is 0.40468564224 hectares per acre. Multiply acres by that number. One acre is 0.4047 hectares. Ten acres is 4.047 hectares. The old memory aid 'divide acres by 2.5' is close to 0.4 and already wrong in the third digit. A section of land in the US, 640 acres, is 258.999 hectares, just under 2.59 km², which matches the square-mile factor in the same table.

Farms, zoning, and listings that cross from acres to hectares. A 5 acre lot is 2.023 hectares. A hectare is about 2.471 acres, so the inverse is divide by 0.40468564224 if you ever need to go back. This page only goes toward hectares.

Exact formula

Formulahectares = acres × 0.40468564224

hectares = acres × 0.40468564224 One ac is 0.40468564224 ha. Ten ac is 4.0468564224 ha. The worked example below uses that same conversion.

Conversion table

The acres column runs from 0.5 ac (0.2023 ha) through 640 ac (259 ha).

Worked example: Acres to Hectares

One international acre is 0.4047 ha. A hectare is 10,000 square metres, and the acre is 4046.8564224 of those, so the factor is 0.40468564224. Dividing by 2.5 is the memory aid that already fails in the third digit. Ten acres is 4.047 ha. A US section of 640 acres is 259 ha, just under 259 hectares. The survey acre, based on the survey foot, is a slightly different historic area. Local words such as morgen or rai are not acres and will not survive this multiplication.

Pitfalls for acres to hectares

• The US survey acre was based on the survey foot and differs slightly from the international acre. This page uses 4046.8564224 m².
• Hectares are not '100 acres' and not '100 square metres'. A hectare is 10,000 m².
• Dividing by 2.5 gives 0.4, not 0.40468564224. Over a large farm the gap is a field.
• Local words (manzana, morgen, rai) are not acres. Do not run them through this factor.