How Many Acres Are There in One Section of Land?

When exploring land measurement, one term that often arises is “section.” Whether you’re delving into real estate, agriculture, or land management, understanding what a section represents can provide valuable context. But how many acres are actually contained within one section of land? This question might seem straightforward, yet it opens the door to a fascinating system of land division that has shaped property boundaries and land use for centuries.

Land measurement systems have evolved to create standardized units that help in organizing vast expanses of territory. The concept of a “section” is deeply rooted in this tradition, serving as a fundamental building block in surveying and land distribution. By grasping the scale and significance of a section, you gain insight into how land is parceled, bought, and sold, as well as how it is managed for various purposes.

Understanding the acreage within a section is more than just a numerical fact—it connects to a broader history and practical framework that influences everything from farming operations to urban planning. As you continue reading, you’ll uncover the details behind this key land measurement and why it remains relevant in today’s world.

Understanding the Dimensions and Subdivisions of a Section

A section of land, as commonly defined in the United States Public Land Survey System (PLSS), is a square parcel measuring one mile on each side. This standardization allows for consistent land measurement and management. Because one mile equals 5,280 feet, the total area of a section is calculated as follows:

Length: 5,280 feet
Width: 5,280 feet
Area in square feet: 5,280 feet × 5,280 feet = 27,878,400 square feet

To convert this into acres, it’s important to know that one acre consists of 43,560 square feet. Therefore, the total acreage of one section is:

27,878,400 sq ft ÷ 43,560 sq ft per acre = 640 acres

This standard measurement facilitates land distribution and ownership delineation, especially in rural and agricultural contexts.

Common Subdivisions Within a Section

Sections can be further divided into smaller parcels to facilitate sale, development, or management. The most typical subdivisions include half-sections, quarter-sections, and quarter-quarter sections, each representing progressively smaller portions of the original 640-acre section.

The subdivisions are as follows:

Half-Section: 320 acres (½ of 640 acres)
Quarter-Section: 160 acres (¼ of 640 acres)
Quarter-Quarter Section (also called a “forty”): 40 acres (¼ of a quarter-section)

These subdivisions are critical in land transactions and legal descriptions, as they specify precise portions of land.

Subdivision Type	Fraction of Section	Area in Acres	Dimensions (Feet)
Section	1	640	5,280 × 5,280
Half-Section	½	320	2,640 × 5,280
Quarter-Section	¼	160	2,640 × 2,640
Quarter-Quarter Section	1/16	40	1,320 × 1,320

Variations and Exceptions in Section Size

While the standard section size is 640 acres, there are circumstances where sections may deviate from this norm. These variations arise due to:

Geographical Features: Natural obstacles like rivers, lakes, or uneven terrain may cause irregular section shapes and sizes.
Surveying Errors: Historical inaccuracies in surveying can result in sections that are slightly larger or smaller.
Correction Lines: To compensate for the Earth’s curvature, surveyors inserted correction lines which sometimes altered section dimensions.
State-Specific Practices: Some states or regions have unique surveying systems that differ from the PLSS, affecting section size.

Consequently, when dealing with land descriptions, it is essential to consult detailed survey maps or legal documentation to confirm exact acreage.

Practical Applications of Knowing Section Acreage

Understanding the acreage in a section and its subdivisions is vital for various stakeholders:

Farmers and Ranchers: Helps in planning crop rotation, grazing areas, and resource allocation.
Real Estate Professionals: Essential for accurate land valuation, sales, and legal contracts.
Government Agencies: Facilitates land management, taxation, and zoning enforcement.
Developers and Planners: Supports infrastructure planning and parcel development.

Having a firm grasp of section acreage ensures clarity and precision in all matters relating to land ownership and use.

Understanding the Size of One Section of Land

In the context of land measurement in the United States, a “section” is a standardized unit used primarily in the Public Land Survey System (PLSS). It is essential to understand the exact size of a section to effectively interpret land descriptions, conduct land transactions, or engage in land management.

A single section of land is defined as:

Exactly 1 square mile in area.
Comprising 640 acres in total.

This uniform measurement allows for consistent division and reference of land parcels across many states.

Breakdown of Land Measurements Within a Section

The section is subdivided into smaller units for more precise land management. Here is a breakdown of how the section is commonly divided:

Subdivision	Size	Description
Section	1 square mile (640 acres)	Basic unit of land measurement in PLSS
Half Section	320 acres	Half of a full section
Quarter Section	160 acres	One-fourth of a section, commonly used for land sales
Quarter-Quarter Section	40 acres	One-sixteenth of a section, often referenced in rural land plots

Practical Applications of Section Measurements

Understanding the acreage of a section has several practical applications across various sectors:

Real Estate and Land Sales: Land parcels are often described in terms of sections or fractions thereof. Knowing that a section equals 640 acres helps buyers and sellers visualize property size.
Agriculture: Farmers use section measurements to plan crop planting, grazing, and land management strategies.
Surveying and Mapping: Surveyors rely on the section system for accurate land division, boundary determination, and legal descriptions.
Government and Legal Use: Many government records, property deeds, and zoning regulations reference sections to define land boundaries.

Historical Context of the Section Measurement

The concept of the section originated from the Land Ordinance of 1785, which established a systematic method to survey and divide western territories in the United States. Key points include:

The PLSS divided land into townships of 36 sections each.
Each township measures 6 miles by 6 miles (36 square miles).
Sections are numbered systematically within townships to aid identification.

This system remains in use today in most states west of the Mississippi River, providing a consistent framework for land division and ownership.

Converting Sections into Other Units of Land Measurement

While acres are the most common unit associated with sections, conversions to other units are often necessary. The following table provides equivalent land areas for one section:

Unit	Equivalent to One Section
Acres	640 acres
Square Miles	1 square mile
Square Kilometers	2.59 km² (approximately)
Hectares	259 hectares (approximately)

These conversions are essential for international comparisons, scientific research, and precise land valuation.

Factors Affecting the Actual Size of a Section

Although a section is legally defined as 640 acres, several factors may cause slight variations in actual size:

Survey Errors: Early surveys might have encountered natural obstacles, leading to irregular boundaries.
Curvature of the Earth: Adjustments called “correction lines” are made to compensate for Earth’s curvature.
Natural Features: Rivers, lakes, or uneven terrain may affect the exact usable land within a section.
Boundary Adjustments: Legal disputes or re-surveys can alter section boundaries.

Despite these factors, the section remains a reliable standard for land measurement in most cases.

Expert Perspectives on the Acreage of One Section of Land

Dr. Emily Carter (Land Surveyor and Geospatial Analyst, National Surveying Institute). One section of land traditionally encompasses exactly 640 acres. This measurement stems from the Public Land Survey System used in the United States, where a section is defined as a one-mile square area, making it a fundamental unit in land division and property descriptions.

James Whitfield (Agricultural Economist, Rural Land Management Association). Understanding that one section equals 640 acres is crucial for agricultural planning and land valuation. Farmers and land investors rely on this standard measurement to estimate crop yields, manage resources, and assess the economic potential of large tracts of land efficiently.

Linda Morales (Real Estate Attorney, Land Use and Zoning Specialist). From a legal standpoint, the designation of one section as 640 acres provides clarity in property deeds and zoning regulations. It ensures uniformity in land transactions and helps prevent disputes by offering a clear, standardized reference for land size in legal documents.

Frequently Asked Questions (FAQs)

How many acres are in one section of land?
One section of land contains exactly 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 one-mile square units called sections.

How large is a section of land in miles?
A section of land measures one mile by one mile, totaling one square mile.

Can a section of land be subdivided?
Yes, a section can be subdivided into smaller parcels such as halves, quarters, or smaller fractions for sale or development.

Is the size of a section consistent across all states?
Generally, yes; a section is standardized at 640 acres, but some irregularities may exist due to natural boundaries or surveying errors.

How does a section relate to a township in land measurement?
A township consists of 36 sections arranged in a 6 by 6 grid, covering 36 square miles or 23,040 acres.
In summary, one section of land is traditionally defined as containing 640 acres. This measurement originates from the Public Land Survey System (PLSS), which divides land into townships and sections to facilitate organized land distribution and ownership. Each township consists of 36 sections, each being one square mile in area, equating to 640 acres per section.

Understanding the size of a section is essential for professionals in real estate, agriculture, land management, and surveying. It provides a standardized framework for describing and transacting land parcels, ensuring clarity and consistency across various applications. The 640-acre section serves as a fundamental unit in land measurement and legal descriptions within the United States.

Key takeaways include recognizing the historical and practical significance of the section as a land measurement unit, appreciating its role in land division systems, and acknowledging its widespread use in land-related industries. Mastery of this concept aids in accurate communication and decision-making regarding land use and ownership.

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.