Acre to Hectare and Hectare to Acre Converter (acre to ha, ha to acre)

Verified by the ConvertReference Technical Standards Team

ConvertReference Technical Standards Team

All values and formulas are validated through our editorial review process and cross-checked against internationally recognized reference standards (NIST, BIPM, CODATA).

View Editorial Standards & Report Corrections

Last reviewed: December 04, 2025

Conversion Factors

1 acre = 0.404687260987425 hectare
1 hectare = 2.47104393046628 acre

(Exact factors: 0.404687260987425 and 2.47104393046628)

Sources: NIST · BIPM

About this Acre and Hectare Converter

This quick, user-friendly tool makes it easy to compare acres and hectares. Use the swap button to switch between units anytime. See clear results as you explore different area sizes. Perfect for planning and everyday measurements.

What are Acres and Hectares?

What is an Acre?

Acre (ac) is a unit of area used in the Imperial and US customary systems. It equals 43,560 square feet, exactly 1/4 of a square mile, or 4,046.8564224 square meters. Common symbol: ac. One real-world example: a football field (including end zones) covers about 1.32 acres.

What is a Hectare?

A hectare is a metric unit of area equal to 10,000 square meters (1 ha = 10,000 m²). It belongs to the metric system and is a widely used non-SI unit for land area; symbol: ha. It can be thought of as a square 100 m on each side. Real-world example: about the size of 1.5 football (soccer) fields, or roughly 0.01 square kilometers.

When to Use Acre vs Hectare

Acre Usage

The acre is used for land area in the United States, Canada, the United Kingdom, and Ireland. It remains a customary unit in property descriptions and land records.

Hectare Usage

Used to express land area. It is common in countries such as India, Australia, Canada and the United Kingdom, where land measurements are typically given in hectares (1 ha = 10,000 m²).

How to Convert Between Acres and Hectares

Conversion Formulas

Acre to Hectare:
acre × 0.404687260987425 = hectare

Hectare to Acre:
hectare × 2.47104393046628 = acre

Step-by-Step Guide

Acre to Hectare

Take your value in acres.
Multiply by 0.404687260987425.
The result is in hectares.

Hectare to Acre

Take your value in hectares.
Multiply by 2.47104393046628.
The result is in acres.

Example: Convert 2 acres to hectares.

Exact: 2 × 0.404687260987425 = 0.80937452197485 hectares.
Rounded: approximately 0.809375 hectares.

Example: Convert 5 hectares to acres.

Exact: 5 × 2.47104393046628 = 12.3552196523314 acres.
Rounded: approximately 12.3552 acres.

History & Context

An acre arose in old England as a practical farming unit, tied to the field size a laborer could till in a day with a team of oxen, and such fields spread with English influence to colonies, where the acre became common in rural maps and land deeds. The hectare was created with the metric system to provide a simple, universal land measure, and it was adopted by many countries as they joined modern scientific standards. Over time both units were used to describe field size, with the acre remaining common in some places and the hectare becoming standard in many others, reflecting shifts in farming, administration, and international trade.

Practical Use

Farmers negotiating a land sale might need to convert acres to hectares to align with metric contracts. They compare pricing and regulatory maps that use hectares rather than acres. In another common scenario, a developer with plans in hectares will convert to acres to present the figures to buyers and regulators who work in acres. Having a quick acre-to-hectare and hectare-to-acre tool helps ensure accurate budgeting and clear communication.

Common Mistakes When Converting Between Acres and Hectares

Confusing acres with hectares and treating them as the same unit.
Using a length conversion factor instead of an area conversion factor.
Rounding or truncating results too early without considering precision.
Misreading abbreviations by treating ha and ac as interchangeable.

Mental Shortcuts for Quick Conversions

Acre to hectare: 1 ha ≈ 2.47 acres; multiply acres by 0.4047 to estimate. Hectare to acre: use the reciprocal ≈ 2.471; multiply hectares by 2.471 (or divide by 0.4047). This is for estimation only; use a precise converter in most situations.

Acres and Hectares Conversion Graph

Conversion Table for Acre and Hectare

Common conversion values
Acres	Hectares
1	0.404687
2	0.809375
5	2.02344
10	4.04687
25	10.1172
50	20.2344
100	40.4687
200	80.9375
500	202.344
1000	404.687

Values are rounded for display; internal calculations use the exact conversion factors between acre and hectare (0.404687260987425 and 2.47104393046628).

Dataset & API Access

Programmatic Access

Free JSON API with stable endpoints and predictable keys for automated bidirectional conversions.

Endpoint: https://convertreference.org/api/v1/convert/acre-to-hectare.json

Content Type: application/json

Documentation: View API docs

Licensing

License: CC0 1.0 Universal (Public Domain)

See all datasets

Data & Editorial Process

All numerical values and formulas are generated from the Pint scientific unit library (v0.25), using constants consistent with the BIPM SI Brochure (9th Edition) and NIST Special Publication 811. Explanatory text is drafted with AI assistance and reviewed by ConvertReference editors for clarity and accuracy. This converter is completely free to use, and all calculations are performed locally in your browser and never sent to a server.

2025-12-04 – Generated: Page created using Pint v0.25 verified constants.
2025-12-04 – Reviewed: Verified by ConvertReference editors; no numerical changes required.

⚠️ Report this page ⬆️ Go to top