acre → hectare | Converter

Convert acre to hectare with the formula below. 1 ac ≈ 0.40468564224 ha

Quick Insight

1 acre = 0.404686 hectare

5 ac ≈ 2.0234282112 ha. Because the destination unit is larger, the numeric result is smaller for the same positive area.

💡 Tip: Check the source definition, and retain the international-foot basis when sharing the ac → ha result.

Land and habitat summariesRectangular land area

Quick Values:

From

0.40468564224

Formula: ha ≈ ac × 0.40468564224

Rounded factors

Relative rounding difference; not measurement uncertainty.

0.4

2 significant digitsΔ 1.2%

0.404686

6 significant digitsΔ 0.000088%

0.40468564224

12 significant digitsΔ 1.4e-14%

Visual Comparisons

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0.1 ac → 0.04046856422 ha

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0.5 ac → 0.2023428211 ha

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1 ac → 0.4046856422 ha

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2 ac → 0.8093712845 ha

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5 ac → 2.023428211 ha

Mathematical Facts

📐Conversion formula: ha ≈ ac × 0.40468564224

🔄Reverse conversion: ac ≈ ha × 2.47105381467

Convert acre to hectare with the formula below. ha ≈ ac × 0.40468564224. 1 ac ≈ 4,046.8564224 m²; 1 ha ≈ 10,000 m² For ac → ha, keep the original surface unchanged and change only its unit. The acre here is based on the international foot and equals 43,560 ft². It expresses land area without fixing a shape, a side length or a perimeter. Hectares give a compact area for a field or habitat summary. One hectare is 10,000 m², the area of a 100 m by 100 m square, but a hectare need not have a square shape.

Why This Conversion Matters

A field list and a map summary may use different land-area units. Convert their areas before adding or comparing them, and keep the same included boundaries; a new unit does not change what was measured. Because the destination unit is larger, the numeric result is smaller for the same positive area. The calculator uses the full stored factor and rounds displayed results to 12 significant digits. Display precision is not a guarantee of measurement accuracy.

Real-World Examples

Land and habitat summaries

These hypothetical rectangles illustrate how a known area changes units for comparison with a land summary. The second total combines two separate, equal areas. Actual irregular regions require a measured area rather than an assumed rectangle.

Examples:

Rectangular land area: 660 ft × 330 ft = 5 ac ≈ 2.0234282112 ha
Two equal, non-overlapping areas: 10 ac ≈ 4.0468564224 ha

Pro Tips:

✓Combine only non-overlapping areas, and retain the same boundary definition in both units.

Quick Reference Table

acres	hectares
10 ac	4.0468564224 ha
50 ac	20.234282112 ha
100 ac	40.468564224 ha
500 ac	202.34282112 ha
1,000 ac	404.68564224 ha

Formula: ha = ac × conversion factor

History & Background

The CIPM adopted the hectare and its symbol in 1879. Its area is 10,000 m².

Common Mistakes to Avoid

Mixing international-foot acres with another acre definition

The calculator uses 4,046.8564224 m² per acre. An acre based on the U.S. survey foot has a different area, so matching the word alone is insufficient.

✓ Check the source definition, and retain the international-foot basis when sharing the ac → ha result.

Pro Tips

✓Use the international-foot acre in both records; a U.S. survey-foot-based acre or another local land unit needs its own definition.
✓Keep ha distinct from m²: the 100 m side of a one-hectare square must be multiplied by the other 100 m side.
✓Combine only non-overlapping areas, and retain the same boundary definition in both units.

Sources and unit definitions

Frequently Asked Questions

How do I calculate the conversion?

ha ≈ ac × 0.40468564224. 1 ac ≈ 4,046.8564224 m²; 1 ha ≈ 10,000 m²

What is an example?

1 ac ≈ 0.40468564224 ha; 10 ac ≈ 4.0468564224 ha; 100 ac ≈ 40.468564224 ha

What should I check specifically for ac → ha?

The calculator uses 4,046.8564224 m² per acre. An acre based on the U.S. survey foot has a different area, so matching the word alone is insufficient. Check the source definition, and retain the international-foot basis when sharing the ac → ha result. 5 ac ≈ 2.0234282112 ha.

Can this area result determine a perimeter?

No. An area value does not uniquely determine the shape or perimeter. Keep a map or the measured boundary lengths if those are needed; the converter only changes the unit of an existing area.