Instantly Convert Hectares ↔ Acres — Both Directions
Convert hectares to acres (ha → ac) or acres to hectares (ac → ha) instantly. Get exact conversions with formula breakdown, reference table, real-world land examples, and related area unit comparisons — all free, no sign-up needed.
Hectares and acres are both units of land area — the hectare from the metric (SI) system, the acre from the imperial and US customary system. Our converter handles both directions instantly using the exact internationally defined conversion factor.
The hectare (symbol ha) is the standard metric unit of land area, equal to 10,000 square metres or one square hectometre (100 m × 100 m). It is widely used in agriculture, forestry, urban planning, and land management across Europe, Australia, Africa, and most metric countries. One hectare is equivalent to 2.47105 acres and is roughly the size of a typical city block or a standard international football pitch with surrounding area.
The acre (symbol ac) is the primary unit of land area in the United States, United Kingdom, and other countries using the imperial or US customary system. One acre is defined as exactly 4,046.8564224 square metres (or 43,560 square feet). It originates historically as the area a yoke of oxen could plough in a day. Today it remains the standard for land sales, farming, and real estate in the US and UK. One acre = 0.404686 hectares.
The exact conversion factor is 1 hectare = 2.47105381 acres, derived from the SI definition of the hectare (10,000 m²) and the international definition of the acre (4,046.8564224 m²). For the reverse direction: 1 acre = 0.40468564 hectares. All conversions on this page use these exact internationally defined factors — no rounding in the base calculation.
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The conversion between hectares and acres uses a single exact multiplication factor. One hectare is defined as 10,000 m² and one acre as 4,046.8564224 m² — dividing these gives the exact conversion ratio. Both formulas below are mathematically precise using the internationally defined values for both units.
The table below shows common hectare values converted to acres, along with square metres and square kilometres for full context. All values use the exact factor of 1 ha = 2.47105381 ac. For acres to hectares, use the reverse converter or the table below.
| Hectares (ha) | Acres (ac) | Square Metres (m²) | Square km (km²) | Typical Land Reference |
|---|---|---|---|---|
| 0.1 ha | 0.247 ac | 1,000 m² | 0.001 km² | Large residential plot |
| 0.5 ha | 1.236 ac | 5,000 m² | 0.005 km² | Small community park |
| 1 ha | 2.471 ac | 10,000 m² | 0.01 km² | Standard football pitch area |
| 2 ha | 4.942 ac | 20,000 m² | 0.02 km² | Small farm plot |
| 5 ha | 12.355 ac | 50,000 m² | 0.05 km² | Small vineyard / orchard |
| 10 ha | 24.711 ac | 100,000 m² | 0.10 km² | Medium farm field |
| 20 ha | 49.421 ac | 200,000 m² | 0.20 km² | Large suburban development |
| 40 ha | 98.842 ac | 400,000 m² | 0.40 km² | Small golf course |
| 50 ha | 123.553 ac | 500,000 m² | 0.50 km² | Large farm paddock |
| 100 ha | 247.105 ac | 1,000,000 m² | 1.00 km² | 1 km² — small village area |
| 200 ha | 494.211 ac | 2,000,000 m² | 2.00 km² | Medium agricultural estate |
| 500 ha | 1235.527 ac | 5,000,000 m² | 5.00 km² | Large cattle station section |
| 1000 ha | 2471.054 ac | 10,000,000 m² | 10.00 km² | Large national park section |
The table below shows common acre values converted to hectares and square metres. Use this when working with US or UK land specifications and needing metric equivalents for international comparison, planning applications, or agricultural reporting.
| Acres (ac) | Hectares (ha) | Square Metres (m²) | Square Feet (ft²) |
|---|---|---|---|
| 0.25 ac | 0.1012 ha | 1,011.7 m² | 10,890 ft² |
| 0.5 ac | 0.2023 ha | 2,023.4 m² | 21,780 ft² |
| 1 ac | 0.4047 ha | 4,046.9 m² | 43,560 ft² |
| 2 ac | 0.8094 ha | 8,093.7 m² | 87,120 ft² |
| 5 ac | 2.0234 ha | 20,234 m² | 217,800 ft² |
| 10 ac | 4.0469 ha | 40,469 m² | 435,600 ft² |
| 20 ac | 8.0937 ha | 80,937 m² | 871,200 ft² |
| 50 ac | 20.234 ha | 202,343 m² | 2,178,000 ft² |
| 100 ac | 40.469 ha | 404,686 m² | 4,356,000 ft² |
| 200 ac | 80.937 ha | 809,371 m² | 8,712,000 ft² |
| 640 ac | 259.000 ha | 2,590,000 m² | 27,878,400 ft² |
The hectare-to-acre conversion is one of the most common land area conversions in agriculture, real estate, urban planning, and environmental science — wherever metric and imperial measurement systems intersect.
Farmers and agronomists routinely convert between hectares and acres when comparing crop yields, applying fertiliser rates, or purchasing land. Yield data from European and Australian farms is reported in tonnes per hectare, while US figures use bushels per acre. Converting between systems enables accurate yield benchmarking and input cost comparisons across international markets.
Land sold in the US and UK is listed in acres, while property in Europe, Australia, and most of Asia is measured in hectares or square metres. Buyers and agents comparing international properties — or UK/Australian buyers looking at US land listings — need reliable hectare-to-acre conversion to understand land size and calculate accurate price-per-area comparisons.
National parks, forest reserves, and conservation areas are reported in hectares in international publications (e.g. IUCN, UN FAO), while US forestry reports use acres. Converting between the two is essential for comparing deforestation rates, protected area statistics, and carbon sequestration capacity across different countries and reporting frameworks.
Planning authorities in metric countries specify development zones in hectares, while US zoning maps use acres. Developers working on international projects, architects preparing feasibility studies, and surveyors comparing international land-use data all need accurate hectare-to-acre conversion to ensure planning compliance and consistent site area reporting.
Climate reports, deforestation studies, and land-use change analyses published by international bodies (UN, World Bank, EU) use hectares as the standard area unit. Converting to acres allows US-based audiences and policymakers to contextualise these figures — for example, understanding that the Amazon loses approximately 1.5 million hectares (3.7 million acres) of forest annually.
Geography, ecology, and environmental science students regularly convert between hectares and acres in coursework, lab reports, and research papers. Understanding land area at both human and landscape scales — from a 0.5 ha school field to a 10,000 ha watershed — is a fundamental skill in spatial sciences. The relationship 100 ha = 1 km² also makes hectares essential for metric spatial analysis.
The Food and Agriculture Organisation of the United Nations publishes global agricultural land use data in hectares — including arable land, permanent crops, and pastures by country. Essential for comparing farm sizes and agricultural output across metric and imperial countries.
FAO Land Use Statistics →The National Institute of Standards and Technology (NIST) provides the official US definition of the acre and its exact relationship to SI units. Their unit conversion reference is the authoritative source for the exact factor 1 acre = 4,046.8564224 m² used in all conversions on this page.
NIST Unit Conversions →The International Bureau of Weights and Measures (BIPM) officially approves the hectare as a non-SI unit accepted for use with the SI system. Their SI Brochure formally defines the hectare as exactly 1 hm² = 10⁴ m², confirming it as the internationally recognised standard for land area measurement.
BIPM SI Units Reference →