Acre to Hectare Conversion Guide — Farmers & Buyers 2026

One acre is 0.404686 hectares, and one hectare is 2.47105 acres. This guide covers the formula, the history behind both units, and the numbers farmers and buyers actually use.

The formula

hectares = acres × 0.404686. acres = hectares × 2.47105. One hectare is a square 100 m on each side — exactly 10,000 m².

Quick reference

1 ac = 0.40 ha · 5 ac = 2.02 ha · 10 ac = 4.05 ha · 25 ac = 10.12 ha · 50 ac = 20.23 ha · 100 ac = 40.47 ha · 640 ac = 259 ha (one square mile).

Where each unit is used

Acres dominate the US, UK and India for land sale; hectares are standard across the EU, Australia, Canada and in all agricultural statistics and subsidy paperwork.

The origin of the acre

An acre was the area one man with one ox could plough in a day — a furlong (220 yd) long by a chain (22 yd) wide, which is 4,840 square yards or 4,046.86 m².

Other land units you'll meet

1 bigha (varies by Indian state, ~1,600–2,700 m²) · 1 guntha = 101.17 m² · 1 cent = 40.47 m² · 1 rood = 0.25 acre · 1 square mile = 640 acres = 259 hectares.

Practical scale checks

A football pitch is roughly 1.76 acres (0.71 ha). A typical UK residential plot is 0.1–0.2 acre. A commercial dairy farm in the EU averages 60–100 ha.

How this guide is researched and fact-checked

This article is produced by the ToolKit Pro Measurement Desk using ai-assisted research with human editorial verification against primary sources, and is checked by a human editor at the ToolKit Pro editorial desk before publication. Every number, formula and threshold quoted here is traced back to a primary standards body or health authority rather than to another blog, and each figure is re-computed with our own calculators so the worked examples and the live tools on this site always agree. When a definition changes — as with the 2019 SI redefinitions — the affected articles are re-checked and the “updated” date above is bumped.

Produced by: ToolKit Pro Measurement Desk — Unit conversion & measurement standards
Method: AI-assisted research, human-verified against primary sources
Reviewed by: ToolKit Pro editorial desk (human review)
Last reviewed: 2026-08-19
Corrections: spotted an error? Tell us and we will fix and re-date the page.

Sources & further reading

BIPM — The International System of Units (SI Brochure)
NIST — Guide for the Use of the International System of Units
WHO — Body weight & health guidance

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