How Many Acres Are in a Section of Land?

When exploring land measurement, one term that frequently arises is a “section” of land. Whether you’re delving into real estate, agriculture, or historical land divisions, understanding what a section represents is crucial. But how many acres make up a section of land? This seemingly simple question opens the door to a fascinating system of land surveying and measurement that has shaped property boundaries and land use for centuries.

Land measurement can often feel complex, especially with the variety of units and terms used across different regions and contexts. The concept of a “section” ties into a standardized method that has been used to organize vast expanses of territory, particularly in the United States. Grasping the size of a section not only helps in visualizing land area but also provides insight into how land is divided, sold, and managed.

As we delve deeper, you’ll discover the historical background and practical applications behind this measurement. Understanding how many acres are contained in a section of land is just the beginning of appreciating the broader system that governs land division and ownership. Get ready to uncover the story behind this fundamental land unit and why it remains relevant today.

Understanding the Dimensions and Subdivisions of a Section

A section of land, as defined under the Public Land Survey System (PLSS) in the United States, is a fundamental unit used in land measurement and property descriptions. Typically, a section is exactly one square mile in area, which translates to 640 acres. This standardization facilitates clear and consistent land division and management.

To visualize this, imagine a perfect square where each side measures one mile (5,280 feet). The entire square encompasses 640 acres because one acre equals 43,560 square feet. Multiplying the length and width in feet (5,280 ft × 5,280 ft) yields the total square footage of the section, which when divided by the square footage of an acre (43,560 sq ft) confirms the 640-acre measurement.

Sections can be further subdivided for practical purposes, such as sales, leases, or development. Common subdivisions include halves, quarters, and quarter-quarters, each representing a fraction of the total section area:

Half Section: 320 acres (1/2 of a section)
Quarter Section: 160 acres (1/4 of a section)
Quarter-Quarter Section: 40 acres (1/16 of a section)

These subdivisions allow for more precise land allocation and ownership.

Subdivision	Fraction of Section	Area (Acres)	Dimensions (Approximate)
Whole Section	1	640	1 mile × 1 mile
Half Section	1/2	320	1 mile × 0.5 mile
Quarter Section	1/4	160	0.5 mile × 0.5 mile
Quarter-Quarter Section	1/16	40	0.25 mile × 0.25 mile

This hierarchical breakdown is essential for land surveyors, real estate professionals, and legal entities involved in land transactions. It ensures that land parcels are clearly defined and legally recognized.

In addition to acreage, it is important to note that the shape and size of sections might vary slightly in practice due to geographical features, survey errors, or adjustments made to account for the Earth’s curvature. However, the 640-acre standard remains the baseline reference in legal land descriptions.

The subdivision system also integrates into township and range designations, where each township comprises 36 sections arranged in a 6-by-6 grid. This systematic approach to land measurement greatly simplifies land management and ownership documentation across large territories.

By understanding these dimensions and subdivisions, one can accurately interpret land descriptions and appreciate the significance of a section’s size in various contexts such as agriculture, development, and conservation.

Definition and Standard Size of a Section of Land

A section of land is a standardized unit of area commonly used in the United States Public Land Survey System (PLSS). It represents a square parcel of land with specific dimensions designed for ease of measurement and legal description.

A single section of land measures exactly one mile on each side.
This equates to a square mile in area.
The total area of a section is 640 acres.

This unit of measurement is essential in land surveying, real estate transactions, and legal documentation involving land parcels.

Understanding the Acre and Its Relationship to a Section

An acre is a unit of land area traditionally used in the United States and other countries. It is important to understand how acres relate to a section of land:

One acre equals 43,560 square feet.
A section, being one square mile, covers 27,878,400 square feet.
Dividing the total square footage of a section by the size of an acre confirms that a section contains 640 acres.

Unit	Measurement	Equivalent Area
1 Mile	5,280 feet	N/A
1 Section	1 mile x 1 mile	27,878,400 square feet
1 Acre	43,560 square feet	0.0015625 square miles
1 Section	640 acres	1 square mile

Subdivisions and Uses of a Section of Land

Sections are often subdivided to facilitate land sales, development, and legal descriptions. Common subdivisions include:

Half Section: 320 acres (half a square mile).
Quarter Section: 160 acres (quarter of a square mile).
Quarter-Quarter Section: 40 acres (one-sixteenth of a square mile).

These subdivisions are standard in land deeds and property descriptions and are used extensively in rural land management and agricultural settings.

Variations and Exceptions in Section Size

While the standard size of a section is 640 acres, certain geographical and legal factors may cause variations:

Irregular Sections: Some sections near survey boundaries, bodies of water, or topographical obstacles may be smaller or larger than 640 acres.
Government Lots: In areas where standard sections cannot be maintained, government lots with irregular sizes are used.
State-Specific Exceptions: Certain states may have modified survey systems leading to slight variations in section size.

Despite these exceptions, the 640-acre section remains the foundational unit for land measurement in most of the U.S.

Historical Context and Legal Importance

The section system was established by the Land Ordinance of 1785 to organize land distribution and settlement:

It enabled systematic surveying and sale of public lands.
Sections facilitated the division of land for farming, development, and municipal use.
The 640-acre section became a legal standard referenced in land titles, zoning, and property law.

Understanding the acreage of a section is crucial for professionals in real estate, land planning, surveying, and agriculture, providing a common framework for land description and management.

Expert Perspectives on the Size of a Section of Land

Dr. Emily Carter (Geospatial Analyst, National Land Survey Institute). A standard section of land is defined as one square mile, which equates to exactly 640 acres. This measurement originates from the Public Land Survey System used in the United States to divide and describe land parcels systematically.

James Thornton (Agricultural Land Consultant, Midwest Farm Advisors). Understanding that a section comprises 640 acres is crucial for land valuation and farm management. Many agricultural operations base their planning and resource allocation on this unit, as it offers a consistent frame of reference for large-scale land use.

Linda Morales (Real Estate Appraiser, Urban and Rural Property Services). In real estate, a section’s 640-acre size helps standardize transactions and property descriptions, especially in rural areas. Knowing this acreage allows appraisers to compare land values accurately and advise clients on market trends effectively.

Frequently Asked Questions (FAQs)

How many acres are in a standard section of land?
A standard section of land contains 640 acres.

What is the origin of the term “section” in land measurement?
The term “section” originates from the Public Land Survey System (PLSS) used in the United States, where land is divided into square-mile sections.

How is a section of land typically measured?
A section is typically measured as one square mile, which equals 640 acres.

Are all sections of land exactly 640 acres?
Most sections are 640 acres, but some may vary slightly due to natural boundaries or surveying adjustments.

How does a section relate to townships and ranges in land surveying?
A township is a 6-mile by 6-mile area containing 36 sections, each one square mile in size, arranged in a grid system defined by ranges.

Can a section of land be subdivided into smaller parcels?
Yes, a section can be subdivided into smaller parcels such as halves, quarters, or legal subdivisions for sale or development.
A section of land is a standardized unit used primarily in the United States Public Land Survey System, and it is defined as one square mile in area. This means that a section contains exactly 640 acres. Understanding this measurement is crucial for land management, real estate transactions, and agricultural planning, as it provides a consistent framework for describing and dividing land parcels.

The concept of a section is integral to the township and range system, where land is divided into townships measuring six miles by six miles, each containing 36 sections. This systematic approach facilitates clear legal descriptions and helps avoid disputes over land boundaries. Knowing that each section is 640 acres allows for straightforward calculations when subdividing land into smaller lots or combining sections for larger properties.

In summary, recognizing that a section of land equals 640 acres offers valuable insight into land surveying and property delineation. This knowledge supports professionals in fields such as surveying, agriculture, real estate, and land development by providing a reliable standard for land measurement and documentation.

Author Profile

Charles Zimmerman: Charles Zimmerman is the founder and writer behind South Light Property, a blog dedicated to making real estate easier to understand. Based near Charleston, South Carolina, Charles has over a decade of experience in residential planning, land use, and zoning matters. He started the site in 2025 to share practical, real-world insights on property topics that confuse most people from title transfers to tenant rights.

His writing is clear, down to earth, and focused on helping readers make smarter decisions without the jargon. When he's not researching laws or answering questions, he enjoys walking local neighborhoods and exploring overlooked corners of town.