Acres to Hectares Converter (ac to ha)
Convert acres to hectares instantly. 1 ac = 0.4047 ha. Includes the formula, a full conversion table and a calculator that works offline.
The formula
To convert acres to hectares, multiply by 0.4047:
ha = ac × 0.4047Going the other way, divide instead — or multiply by 2.471, which is the same thing:
ac = ha × 2.471Acres to Hectares conversion table
| Acres | Hectares |
|---|---|
| 1 ac | 0.4047 ha |
| 2 ac | 0.8094 ha |
| 3 ac | 1.214 ha |
| 4 ac | 1.619 ha |
| 5 ac | 2.023 ha |
| 6 ac | 2.428 ha |
| 7 ac | 2.833 ha |
| 8 ac | 3.237 ha |
| 9 ac | 3.642 ha |
| 10 ac | 4.047 ha |
| 15 ac | 6.07 ha |
| 20 ac | 8.094 ha |
| 25 ac | 10.117 ha |
| 30 ac | 12.141 ha |
| 40 ac | 16.187 ha |
| 50 ac | 20.234 ha |
| 75 ac | 30.351 ha |
| 100 ac | 40.469 ha |
| 250 ac | 101.17 ha |
| 500 ac | 202.34 ha |
| 1000 ac | 404.69 ha |
Hectares to Acres
| Hectares | Acres |
|---|---|
| 1 ha | 2.471 ac |
| 2 ha | 4.942 ac |
| 3 ha | 7.413 ac |
| 4 ha | 9.884 ac |
| 5 ha | 12.355 ac |
| 6 ha | 14.826 ac |
| 7 ha | 17.297 ac |
| 8 ha | 19.768 ac |
| 9 ha | 22.239 ac |
| 10 ha | 24.711 ac |
What that actually looks like
A conversion factor is hard to judge on its own. These are quantities most people already have a feel for, converted for you:
- A football pitch is about 1.8 acres — 0.7284 ha
- A small farm might be 50 acres — 20.234 ha
Why both units are still in use
Area conversions turn up mostly in property listings and land. Homes are advertised in square feet in the US and India, in square metres across most of Europe, and in both in the UK depending on the agent. Land is measured in acres or hectares, which is a separate pair of units again.
Mistakes worth avoiding
Square units do not scale the way linear ones do. A square metre is not 3.28 square feet — it is 3.28 squared, which is 10.76. Doubling a room's dimensions quadruples its area, and forgetting that is how flooring gets ordered short.
The other habit worth breaking is rounding too early. Convert first, round once at the end, and you avoid the drift that turns a small approximation into a visible error by the third calculation.
Doing it in your head
When you only need a rough answer, divide by 2.5 — which lands within 1.2 percent of the true value. Ten acres works out at roughly 4 hectares that way, against 4.047 exactly. An estimate is enough for deciding whether something will fit or whether a figure sounds plausible. When the number has to be right — because you are buying, cooking or building to it — use the calculator and let it carry the decimals.
Common questions
How many hectares are in one acre?
One acre equals 0.4047 hectares. The calculator above handles any value, including decimals and very large numbers, and updates as you type.
Is this an exact conversion?
The factor is accurate to the precision shown, which is far beyond what any practical measurement requires. The table rounds for readability; the calculator does not.
Does this work offline?
Yes. The conversion runs in your browser with no network request, so it works on a plane, in a basement, or on a phone with no signal once the page has loaded.