FORMULA
How to convert
ha = ac × 0.40468564224Example: 10 ac = 4.04685642 ha.
AC → HA
Acres to Hectares
Convert acres to hectares with an exact, deterministic calculation.
LIVE CONVERSIONDECIMAL ENGINE EXACT_
1 ac = 0.40468564224 ha
MULTI-CONVERT
QUICK ANSWER
1 Acre
0.40468564224 ha
REFERENCE TABLE
Acre to Hectare
| acres | hectares |
|---|---|
| 1 ac | 0.40468564 ha |
| 5 ac | 2.02342821 ha |
| 10 ac | 4.04685642 ha |
| 25 ac | 10.11714106 ha |
| 50 ac | 20.23428211 ha |
| 100 ac | 40.46856422 ha |
ABOUT THIS CONVERSION
Convert acres to hectares
Acres remain common in US and UK land descriptions; hectares are widely used for metric agriculture and large property areas. One international acre is exactly 4,046.8564224 square meters, so it equals exactly 0.40468564224 hectare.
Real-world example
A 100 acre property is 40.46856422 ha. Boundary surveys and title documents control the legal area; converting the stated number does not correct an imprecise or disputed measurement.
Rounding and precision
Property and planning figures may be rounded to whole square units, but material estimates should retain enough precision before adding a separate waste allowance. Never hide measurement uncertainty behind many converted decimal places.
Regional context
Hectares and square meters dominate metric land measurement. Acres remain common in the United States, United Kingdom, and several other countries. Property conventions and legal survey records vary, so use the unit stated in the governing document.
Common mistake
Do not assume one hectare equals two acres exactly. One hectare is about 2.47105 acres, and the difference matters for land valuation or application rates.
Editorial method
Definitions and sources are listed below. Calculations retain more precision than the default display and round only for presentation.
USEFUL ANSWERS
ac to ha FAQs
How many hectares are in one acre?
One international acre is exactly 0.40468564224 hectare.
Are all historical acres identical?
No. Historical and regional acre definitions varied; modern calculations normally mean the international acre.
How do I convert acres to hectares?
Enter the ac value in the calculator. It applies the stored factor and offset definitions and returns the equivalent in ha; the formula and common-value table are shown on this page.
Is the ac to ha conversion exact?
Defined measurement relationships are calculated with decimal arithmetic from stored standards. The displayed answer may be rounded for readability. Currency results instead depend on the dated reference rate shown.
FROM UNIT
Acre
One acre (ac) equals 4046.8564224 square meter units (m²) in the converter's reference scale. It measures two-dimensional surface area, so its relationship reflects squared length.
NIST Guide to the SI, SP 811 ↗Definition verified 14 August 2026TO UNIT
Hectare
One hectare (ha) equals 10000 square meter units (m²) in the converter's reference scale. It measures two-dimensional surface area, so its relationship reflects squared length.
NIST Guide to the SI, SP 811 ↗Definition verified 14 August 2026Content reviewed by Akhil Saroop · 16 August 2026 · Report an error on this page