Acre to Hectare (ac to ha)
Result
0.4046856422 Hectare
Formula
ha = ac × 0.4046856422
1 ac = 0.4046856422 ha, and 1 ha = 2.471053815 ac.
Area factors are the square of the length factor: 1 ft = 0.3048 m, so 1 ft² = 0.3048² = 0.09290304 m². The acre is 43,560 ft² (4,046.8564224 m²) and the hectare 10,000 m².
Worked examples
- 1 ac × 0.4046856422 = 0.40468564 ha
- 2.5 ac × 0.4046856422 = 1.0117141 ha
- 10 ac × 0.4046856422 = 4.0468564 ha
- 640 ac × 0.4046856422 = 258.99881 ha
Things to know about ac to ha
- One acre is 0.40468564 ha; one hectare is 2.4711 acres.
- 640 acres make a square mile, which is 259.0 hectares.
Acre to Hectare table
| Acre (ac) | Hectare (ha) |
|---|---|
| 1 | 0.40468564 |
| 2 | 0.80937128 |
| 2.5 | 1.0117141 |
| 5 | 2.0234282 |
| 10 | 4.0468564 |
| 20 | 8.0937128 |
| 50 | 20.234282 |
| 100 | 40.468564 |
| 640 | 258.99881 |
| 1,000 | 404.68564 |
The units
- Acre (ac)
- 43,560 square feet, exactly 4,046.8564224 m². 640 acres make a square mile.
- Hectare (ha)
- 10,000 m² — a square 100 m on each side.
Sources for these factors
- Handbook 44 (2024), Appendix C: General Tables of Units of Measurement — NIST
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy