About the Acres to Hectares Converter
This acres to hectares converter turns a land area in acres — the unit used in the US, UK and several Commonwealth countries — into hectares, the metric land unit used almost everywhere else. It also gives the area in square meters, square kilometers and square feet so you can compare plots, farms, parks and building sites in any unit.
Farmers reading international crop-yield or subsidy figures, land buyers comparing listings across countries, foresters, surveyors and students all run into this conversion. The table covers common sizes from a quarter-acre house lot up to a 640-acre square mile.
One international acre is exactly 4,046.8564224 m², so one acre is about 0.4047 hectares. A handy mental shortcut: hectares ≈ acres × 0.4, or acres ÷ 2.5.
With the default inputs, the hectares is 4.0469 ha. Change any value above to recalculate instantly.
How to use the acres to hectares converter
- 1Enter the land area in acres (decimals are fine, e.g. 0.25).
- 2Read the result in hectares.
- 3Check square meters, square kilometers or square feet if needed.
- 4Use the table for common plot and farm sizes.
Formula and method
An international acre is 43,560 square feet. Because a foot is exactly 0.3048 m, one acre equals 43,560 × 0.09290304 = 4,046.8564224 m². A hectare is 10,000 m² (a 100 m × 100 m square), so hectares = acres × 4,046.8564224 ÷ 10,000 = acres × 0.40468564224.
Square kilometers are square meters ÷ 1,000,000 (100 hectares = 1 km²). The US survey acre used in some older land records differs by only about 4 parts per million, which is negligible here.
- ac
- Acres (43,560 sq ft)
- ha
- Hectares (10,000 m²)
Worked examples
10-acre smallholding
10 × 0.40468564224 = 4.05 ha, or 40,468.56 m². In square feet that is 10 × 43,560 = 435,600.
One acre
One acre is exactly 4,046.86 m², a little over 40% of a hectare.
160-acre quarter section farm
A US quarter section is 160 acres: 160 × 0.4047 = 64.75 ha, or about 0.65 km².
Frequently asked questions
How many hectares are in an acre?+
One acre is 0.40468564224 hectares — roughly 0.4 ha. Put the other way, one hectare is about 2.471 acres.
Which is bigger, an acre or a hectare?+
A hectare is bigger: it is 10,000 m², about 2.47 times the size of an acre (4,046.86 m²).
How big is an acre in meters?+
An acre is 4,046.86 square meters. As a square it would measure about 63.6 m × 63.6 m, though traditional acres were long strips of one furlong by one chain (201 m × 20 m).
How many acres are in a square mile?+
A square mile contains exactly 640 acres, which is 258.999 hectares or about 2.59 km².
How do I convert hectares back to acres?+
Multiply hectares by 2.4710538 or divide by 0.4047. For example, 20 ha × 2.471 = 49.42 acres. Use the hectares to acres converter for the full reverse table.