⬜ ac to ha — Acre to Hectare Converter

Convert area units — square meters, acres, hectares, square feet, square kilometers.

1 unit =
From
To
Formula 1 ac = 0.404686 ha
UnitNameValue
Square Meter 4046.86
km² Square Kilometer 0.00404686
ha Hectare 0.404686
ft² Square Foot 43560.057
yd² Square Yard 4840.0064
mi² Square Mile 0.0015625002
Last updated: March 2026

Acre to Hectare Conversion Table

Common acre values converted to hectare — factor: 1 ac = 0.4047 ha

Acre (ac)Hectare (ha)Context
0.01 ac0.004047 haLarge garden
0.1 ac0.04047 haSuburban lot
0.25 ac0.1012 haQuarter acre lot
0.5 ac0.2023 haHalf acre
1 ac0.4047 haFootball field
2 ac0.8094 haCity block
5 ac2.023 haSmall farm
10 ac4.047 haMedium farm
25 ac10.12 haLarge farm
50 ac20.23 haSmall ranch
100 ac40.47 haMedium ranch
250 ac101.2 haLarge ranch
500 ac202.3 haLarge estate
640 ac259 haSquare mile
1,000 ac404.7 haLarge ranch

About Acre to Hectare Conversion

Converting acre to hectare is common in real estate, agriculture, surveying, and construction. Property listings, land records, and planning documents often use different area units depending on the country or industry — making accurate conversion essential for cross-border transactions and international comparisons.

As a practical reference: 5 ac = 2.023 hectare and 10 ac = 4.047 hectare. For larger land areas, 100 ac = 40.47 hectare — a common benchmark for farm and estate valuations. The reverse: 1 ha = 2.471 ac.

All conversions use the internationally recognized factor of exactly 1 ac = 0.4047 ha. Calculations are performed in IEEE 754 double-precision floating point, giving accuracy to at least 8 significant figures — more than sufficient for any practical application.

Quick Answer

Formula: Hectare = Acre × 0.404686

Multiply any acre value by 0.404686 to get hectare. One acre equals 0.404686 ha.

Reverse: Acre = Hectare × 2.4710516

Worked Examples

One acre
1 ac × 0.404686 = 0.404686 ha
1 acre = 0.4047 ha — a standard farm field reference.
One hectare
2.471 ac × 0.404686 = 0.99997911 ha
2.471 acres = 1 hectare — the metric equivalent.
100 acres
100 ac × 0.404686 = 40.4686 ha
100 acres = 40.47 ha — a medium-sized farm.
One square mile
640 ac × 0.404686 = 258.99904 ha
640 acres = 258.999 ha = 1 square mile.

Mental Math Tricks

× 0.4047

Acres × 0.4047 = hectares. Round to × 0.4 for rough estimates (1.2% low).

2.5 ac ≈ 1 ha

Two and a half acres is approximately one hectare — easy mental anchor.

Reverse

ha × 2.471 = acres. Round to × 2.5 for quick estimates.

Who Uses This Conversion?

Farmer

Measures crop fields and pasture in acres for planting, yield, and subsidy calculations.

Real Estate Agent

Lists rural and suburban land parcels in acres for US and UK property transactions.

Land Surveyor

Measures and certifies plot areas in acres for legal property registration.

Mortgage Lender

Assesses collateral value of farmland and rural property quoted in acres.

Government Planner

Allocates land parcels for development, conservation, or infrastructure in acres.

Farmer (India)

Converts acres to local Indian units like bigha, cent, or guntha for local transactions.

Frequently Asked Questions

About Acre and Hectare

Acre (ac)

The acre is a unit of land area equal to 43,560 square feet or about 4,047 m². Its origins trace to medieval England where it represented the amount of land an ox could plough in a day.

Acres remain the standard land measurement unit in the US, UK, Canada, and India for agriculture, real estate, and property transactions.

Interesting fact: A US football field (including end zones) is about 1.32 acres, and a typical suburban house plot in the US is roughly 0.2 acres.

Hectare (ha)

The hectare is a metric unit equal to 10,000 m² or 2.471 acres, defined in 1795 as part of the French metric system. The name comes from the Latin area and the Greek hekaton (hundred).

Hectares are the global standard for agricultural land measurement, forest inventories, nature reserves, and urban planning across metric countries.

Interesting fact: One hectare of wheat can produce about 3-8 tonnes of grain. The Amazon rainforest covers roughly 550 million hectares.