Convert Acre to Hectare (ac → ha)

Converting acres to hectares is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in acres

   Start with the number of acres (ac) you want to convert.
2. 2
   Multiply by 0.404686

   The conversion factor from ac to ha is 0.404686. Multiply your value by this number.
3. 3
   Read the result in hectares

   The result is your value in hectares (ha).

Multiply the value in acres by 0.404686. For the reverse direction, multiply by 2.471054.

• ✓1 acre = 43,560 ft² = 0.4047 ha.
• ✓640 acres = 1 square mile — a "section" in US land survey.
• ✓An acre is 43,560 ft² — a useful number for US real-estate calculations.

• ✗Using "acre" in modern European property — use hectares or m² instead.
• ✗Assuming an acre is a specific shape — it is only an area (any shape).
• ✗Multiplying acres by 4000 m² — correct value is 4046.86.

What is the Acre?

The acre equals exactly 4,046.8564224 square meters (or 43,560 square feet) and is the standard unit for American and British farmland, real estate, and recreational property. The unit's origin is medieval: an acre was the area a yoke of oxen could plow in one day, traditionally a strip 1 furlong (660 ft) by 1 chain (66 ft). Despite metric adoption in many fields, the acre persists in property records throughout the US and UK. A standard American football field (excluding end zones) is about 1.32 acres. The largest US state, Alaska, contains about 365 million acres. The acre relates to the square foot (43,560 ft² = 1 acre), the hectare (1 ha ≈ 2.471 acres), the square mile (640 acres = 1 mi²), and the square meter (1 acre ≈ 4,047 m²). US farms average around 446 acres, and the average UK farm is about 215 acres.

• US farmland and ranches
• UK rural property and estates
• Canadian rural property (legal survey system)

What is the Hectare?

The hectare equals exactly 10,000 square meters (100 m × 100 m) and is the international standard area unit for agricultural land, forestry, and large land development. Adopted as part of the metric system in 1795, the hectare's name combines 'hect-' (one hundred) with 'are' (the basic metric land unit of 100 m²) — meaning 100 ares. A standard FIFA football pitch covers about 0.7 hectares, and Central Park in New York is approximately 341 hectares. Farms across Europe, Latin America, Africa, and Asia are sized in hectares (a small family farm might be 5–20 ha). The hectare relates to the square meter (1 ha = 10,000 m²), the square kilometer (100 ha = 1 km²), the acre (1 ha ≈ 2.471 acres), and the square mile (1 ha ≈ 0.00386 mi²). It is one of the few non-SI units accepted for use with SI for legal land measurement.

• European farm, vineyard and orchard size
• Forestry and conservation land
• Large construction projects and urban development