How to convert acres to hectares
ha = x × 0.40468564224
An international acre is 4,046.8564224 m² and a hectare is 10,000 m². The conversion does not determine usable or buildable land.
Worked example
ha = 5 × 0.40468564224
5 ac = 2.023428 ha.
Conversion table in both directions
Values are generated by the same engine as the interactive converter.
| Input | ac → ha | ha → ac |
|---|---|---|
| 1 | 0.404686 | 2.471054 |
| 5 | 2.023428 | 12.355269 |
| 10 | 4.046856 | 24.710538 |
| 25 | 10.117141 | 61.776345 |
| 50 | 20.234282 | 123.552691 |
| 100 | 40.468564 | 247.105381 |
Unit definitions and sources
Convert area through the shared base unit.
| Unit and system | Use | Definition | Relationship |
|---|---|---|---|
| Hectare (ha); si | Common units | Hectare measures area. m2 = (value in ha) × 10000. Common use: Floor and land area. | Exact definition; numerical display may be rounded |
| Acre (ac); us | Common units | Acre measures area. m2 = (value in ac) × 4046.8564224. Common use: Floor and land area. | Exact definition; numerical display may be rounded |
Sources: BIPM: International System of Units; NIST: SP 811 Appendix B.8: conversion factors; BIPM: SI prefixes
Precision of area conversions
These 2 area units convert through Square meter (m²). 2 have an exact defined relationship to the base unit and 0 are conventional or measured values. Results and the tables on this page come from the same engine, so a table value can be checked against the converter directly.
Standard display shows up to six decimal places, switching to scientific notation for very large or small values. Calculation uses JavaScript binary floating point independently of display rounding, so extra digits are not a claim about measurement accuracy. Each unit lists its own source; a citation records where the definition comes from, not an independent review. See Conversion methodology for the review and correction process.