Free ac to ha calculator

acres to hectares converter

Convert land area from acres to hectares for farming, property, forestry, planning, and international comparisons.

Updated July 20, 2026 Method and assumptions shown below

Convert acres to hectares

Enter any value to calculate the result instantly.

acres to hectares formula

Multiply acres by approximately 0.4046856422. One international acre equals exactly 4,046.8564224 square meters, and one hectare equals 10,000 square meters.

hectares = acres x 0.4046856422

Conversion table

Use these reference values for a quick comparison. The calculator above accepts positive, negative, decimal, and large values when they are meaningful for the quantity.

acreshectares
1 ac0.40468564 ha
2 ac0.80937128 ha
5 ac2.02342821 ha
10 ac4.04685642 ha
50 ac20.23428211 ha
100 ac40.46856422 ha

How to use this converter

Enter the source measurement in the first field. CalUnit applies the displayed formula and updates the destination value immediately. You can use decimals and negative values, copy the result into your work, and compare it with the reference table. Keep the original unit beside the starting measurement so another reader can verify the calculation. For a different unit pair, open the complete area conversion guide or the multi-unit area converter.

When this conversion is useful

Property boundaries depend on survey records, not only a converted advertised area. Keep the original legal unit and stated precision alongside the result.

Accuracy and rounding

The international acre relationship is exact. Historical or local acre definitions can differ, so verify the source for older land records.

Standards references

CalUnit checks physical unit relationships against authoritative measurement references. See the NIST Guide to the SI conversion factors and the BIPM SI Brochure. Regional cooking measures and digital storage conventions are identified separately because their names can represent more than one definition.