Hectares to Acres
Convert any value from hectare to acre with full precision. Use the converter above for instant results, or read on for the exact formula, worked examples, common uses, and answers to frequently asked questions.
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About the Hectare to Acre conversion
Area conversions are essential in real estate, agriculture, construction, and land management. They also show up in everyday tasks like measuring rooms, lawns, floor plans, and plots of land. Because area is a two-dimensional measurement, the conversion factors between units are squared compared to the corresponding length units.
This page focuses specifically on converting hectare to acre. Use the converter above for instant results, or read on for what each unit is, the exact formula, a worked example, and answers to common questions.
Understanding hectare and acre
What is a hectare?
The hectare equals 10,000 square meters, the area of a square 100 meters on each side, and is about 2.47 acres. It is the standard unit for land area, farming, and forestry across most of the world.
What is a acre?
The acre equals exactly 4,046.856 square meters, or 43,560 square feet, and originally represented the area a yoke of oxen could plough in a day. It is the customary unit for land and real estate in the United States and, historically, the British Commonwealth.
How a hectare compares to a acre
The hectare is the larger of the two units: one hectare is about 2.47105381 acre. Because the acre is smaller, the same length or quantity works out to a larger number when you measure it with that unit. Knowing which unit is larger is a quick way to sanity-check a conversion: if the numbers move in the wrong direction, the two units have probably been swapped.
Conversion formula
The exact mathematical relationship between hectare and acre is:
1 hectare = 2.47105381 acre
So to convert a value V from hectare to acre, use:
Vacre = Vhectare × 2.47105381
To go in the opposite direction:
Vhectare = Vacre × 0.40468564
These factors come from the international definitions published by NIST, BIPM, and ISO 80000 and are exact within their respective standard systems. The converter applies them with full floating-point precision.
Worked example
Using the formula above, here are some common values converted from Hectare to Acre:
| Hectare | Acre |
|---|---|
| 1 | 2.471054 |
| 5 | 12.355269 |
| 10 | 24.710538 |
| 25 | 61.776345 |
| 50 | 123.552691 |
| 100 | 247.105381 |
Sources and accuracy
All metric area units derive from the meter (defined by BIPM). The international acre equals exactly 4,046.8564224 m², fixed by the 1959 international yard and pound agreement. The hectare, used worldwide for land measurement, equals exactly 10,000 m².
Conversion factors are cross-checked against the NIST SP 811 guide, the BIPM SI brochure, and ISO 80000, plus published historical references for older unit systems. For mission-critical work such as medical dosing, legal-for-trade measurement, aerospace, or large-scale engineering, always verify independently with the original source.
Practical tips
A useful mental check: 1 acre is roughly the size of a football field (without the end zones), and 1 hectare is about 2.47 acres. When converting large areas, square kilometers and square miles are usually the most practical units.
Frequently asked questions
How many acre are in one hectare?
One hectare equals 2.47105381 acre. To convert, multiply your hectare value by 2.47105381.
Which is bigger, a hectare or a acre?
The hectare is bigger. One hectare equals about 2.47105381 acre.
How accurate is this hectare to acre converter?
It uses the official international conversion factors from NIST and BIPM with full double-precision floating-point accuracy. For everyday use the result is precise to many more decimal places than any practical measurement requires.
Can I convert acre back to hectare as well?
Yes. Use the swap button above to reverse the From and To fields, or change either dropdown to any unit in the area category. The calculation runs entirely in your browser, so it also works offline once the page has loaded.