acres to square meters

American land is bought, sold, and taxed in acres; the international real-estate and agricultural world thinks in square meters and hectares. The legal bridge is exact: since the 1959 yard-and-pound agreement, one acre has been defined as precisely 4,046.8564224 square meters. A one-acre suburban lot is 4,047 m²; a quarter-acre is 1,012 m²; a 40-acre farm parcel is 161,874 m².

1 acre = 4,046.8564224 square meters, and 1 square meter = 2.47105381 × 10−4 acres. One fixed factor covers the whole range: multiply acres by 4,046.8564224. Worked: 10 acres = 40,468.564224 sq m; 100 acres = 404,685.64224 sq m.

By EnginStack Editorial Team | Reviewed against NIST, BIPM and primary-source documentation About →
acres
4,046.8564224 square meters
1 acre = 4,046.8564224 square meters 1 square meter = 0.00024711 acres

Verified against NIST Special Publication 811 and BIPM SI definitions. The conversion factor is exact and traceable to the 1959 treaty constants.

acres to square meters

The acre's metric value is one of the most useful exact constants in real-estate work, because every American deed eventually meets a metric survey. One acre = 4,046.8564224 m² exactly — no rounding, because the 1959 treaty fixed both the yard and the acre simultaneously. Land surveyors working across systems multiply acres by 4,046.8564224 and get square meters to full precision; dividing by the same constant does the reverse. The number also maps neatly to the hectare: 2.4710538 acres make a hectare.

square meters = acres × 4,046.8564224
1 acre = 4,046.8564224 square meters — the 1959 treaty value
The factor is exact by definition.

Worked Examples

Example 1: Convert a quarter-acre residential lot

0.25 × 4,046.8564224 = 1,011.71 m²

Example 2: Convert a 40-acre farm parcel

40 × 4,046.8564224 = 161,874 m²

Example 3: Convert one section of land (640 acres)

640 × 4,046.8564224 = 2,589,988 m²

Common acres to square meters Conversions

acressquare metersContext
0.25 acre1,011.7 m²A quarter-acre residential lot.
1 acre4,046.9 m²The definitional anchor.
2.47 acres10,000 m²Roughly one hectare.
40 acres161,874 m²A standard US farm parcel.
640 acres2,590,000 m²One section — one square mile of land.

Engineering Context

The square meters to acres page inverts this factor. In the area hub, acres to hectares is the farm-world conversion, and acres to square feet handles the US-internal scale. The 640-acre section ties into the length family's mile — a section is one square mile.

The acre began as agricultural geometry: one chain wide by one furlong long, or 66 feet by 660 feet, which is 43,560 square feet. That odd number survives because the US Public Land Survey laid out the country in six-mile-square townships, each divided into 36 sections of one square mile, and each section into 640 acres of exactly 4,046.8564224 square meters. The acre is one of the few US customary units whose legal definition is now metric, so the conversion carries no measurement uncertainty at all. What it does not do is tell you whether the acre was surveyed; older deeds can describe the same nominal area with boundaries that do not close.

More: m² to acres · acres to ha · acres to ft² · Area Guide · Area Hub

Related Unit Converters

square meters to acres Acres to Hectares Acres to Square Feet Area Conversion Guide Area Converters

Frequently Asked Questions

How many square meters is one acre?

Exactly 4,046.8564224 m², per the 1959 yard-and-pound agreement. This is a legal definition, not a rounded figure — the acre's metric value is exact to ten digits.

How many acres are in a hectare?

Exactly 2.4710538146717. A hectare is 10,000 m², and since an acre is 4,046.8564224 m², the ratio is 10,000 / 4,046.8564224.

Why do American deeds still use acres?

Because the US land-survey system — the Public Land Survey System of townships and sections — was built on the acre and the mile in the 18th century, and every parcel boundary since has been recorded in those units. The acre persists by legal continuity, not by preference.