ucUnitCloudInternational unit matrix

Mistake guide

Equating hectare and are

A hectare and an are are roughly the same field measure.

01Assumption

A hectare and an are are roughly the same field measure.

02Actually

One hectare is 100 ares: 10,000 m² against 100 m². The hectare is therefore exactly one hundred times larger.

03Why

The two names sound alike and both belong to agriculture. The are appears in horticulture and with small plots, the hectare with fields and forests — so the two rarely meet in the same order of magnitude.

04Check

Use the square metre figure as the intermediate step: 1 a = 100 m², 1 ha = 10,000 m². Regional measures such as the German Morgen have no single definition and cannot be converted into a fixed number of square metres.

Matching conversions

Hectare to Square metreha → m²AreaSquare metre to Hectarem² → haAreaAre to Square metrea → m²AreaSquare metre to Arem² → aAreaAcre to Hectareacre → haAreaHectare to Acreha → acreArea

Matching tables

TableArea: square metres, hectares and acres

Unit family: Area

Sources

BIPM SI BrochureSI base units, prefixes and official SI context.NIST Guide to SI Appendix BNIST conversion-factor method and non-SI factors.
When not to use

Do not use as the sole basis for official, medical, safety-critical or contractual decisions.

Citation

Citation note: UnitCloud, mistake guide, sources reviewed: September 2026. Source basis: BIPM SI Brochure · NIST Guide to SI Appendix B.