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Acres to Hectares (acre to ha)
Convert acres to hectares: 1 acre = 0.404686 ha. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.
Formula
1 acre = 0.404686 ha
hectares = acres × 0.4046856422 — reverse: acres = hectares × 2.471053815
The factor is derived from the SI definitions of both units (base unit: m2) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.
Worked examples
- 5 acre = 2.02343 ha
- 12.5 acre = 5.05857 ha
- 100 acre = 40.4686 ha
Acres to hectares conversion table
| Acres (acre) | Hectares (ha) |
|---|---|
| 1 | 0.404686 |
| 2 | 0.809371 |
| 3 | 1.21406 |
| 4 | 1.61874 |
| 5 | 2.02343 |
| 6 | 2.42811 |
| 7 | 2.8328 |
| 8 | 3.23749 |
| 9 | 3.64217 |
| 10 | 4.04686 |
| 15 | 6.07028 |
| 20 | 8.09371 |
| 25 | 10.1171 |
| 30 | 12.1406 |
| 40 | 16.1874 |
| 50 | 20.2343 |
| 75 | 30.3514 |
| 100 | 40.4686 |
| 200 | 80.9371 |
| 250 | 101.171 |
| 500 | 202.343 |
| 1000 | 404.686 |
FAQ
How many hectares are in one acre?
1 acre = 0.404686 ha. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.
What is the formula to convert acres to hectares?
Multiply the value in acres by 0.4046856422: hectares = acres × 0.4046856422. For example, 5 acre = 2.02343 ha.
How do I convert hectares back to acres?
Multiply by the inverse factor 2.471053815 (acres = hectares × 2.471053815), or use the hectares-to-acres page.
Related conversions
Machine access
- API:
GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=acre&to_unit=ha - MCP: server
https://tttkmbb.com/mcp, toolconvert_unitswith{"value":5,"from_unit":"acre","to_unit":"ha"} - Markdown: https://tttkmbb.com/conversion/acres-to-hectares.md · JSON: https://tttkmbb.com/conversion/acres-to-hectares.json (add
?value=for a result) · Units: /api/v1/units?quantity=area - OpenAPI operationId:
convert_units. Freshness:static. Authentication: none.