Aliquot Parts, PLSS Definition
The fractional subdivisions of a section created by systematically halving or quartering the land unit.
Full Definition
In the Public Land Survey System, aliquot parts are the standard fractional divisions used to describe land within a section. The term comes from mathematics, where an aliquot part divides evenly into a whole number. In PLSS practice, this means dividing sections into halves and quarters in a consistent, repeatable way.
A full section contains 640 acres. Dividing it once produces half-sections of 320 acres each (N2, S2, E2, or W2). Dividing a half-section again produces quarter-sections of 160 acres (NE, NW, SE, SW). Dividing a quarter-section a third time produces quarter-quarter sections of approximately 40 acres — the smallest standard aliquot division in the system.
Legal descriptions using aliquot parts are written from the smallest unit to the largest. For example, "NESW 14 5N 3W 6th Meridian" identifies the northeast quarter of the southwest quarter of Section 14. Reading this description, a surveyor starts at the section level, locates the southwest quarter (160 acres), then finds the northeast corner of that parcel (40 acres) — the specific piece being described.
Aliquot parts are used whenever land fits neatly into the standard grid. When parcels are irregular — due to water bodies, survey errors, or exterior boundaries — they are assigned as government lots rather than aliquot parts. Understanding aliquot notation is fundamental to reading any PLSS-based deed, title, or legal description in the 30 states covered by the survey system.
Related Terms
Quarter Section
One-fourth of a section, approximately 160 acres, designated as NE, NW, SE, or SW.
Land UnitsQuarter-Quarter Section
One-sixteenth of a section, approximately 40 acres, formed by subdividing a quarter section into four equal parts.
Land UnitsSection
A one-square-mile unit of land within a township, nominally 640 acres, identified by a number from 1 to 36.
Legal Description TermsLegal Land Description
A formal, standardized text description of a land parcel's location using PLSS coordinates — aliquot parts, section, township, range, and principal meridian.
Land UnitsGovernment Lot
A numbered irregular parcel within a section that cannot be described as a standard aliquot part, usually found along water boundaries or exterior survey lines.