Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — STATE/MO/COUNTY/MERCER

Mercer County, MO ZIP codes

Mercer County, MO has 3 ZIP codes, in 3 towns: 64673, 64661 and 64632. 1 more crosses into it from a neighbouring county: 64667.

The county seat is Princeton.

ZIP codes
3
Partly in it
1 more
Towns
3
County seat
Princeton
County FIPS
29129
Population
3,482
Median household income
$62,679
Land area
454 sq mi

Mercer County ZIP codes by town

Princeton (county seat)
64673

Each ZIP code is listed under the county most of its land lies in and the town the Postal Service names it for; a ZIP code's own page shows exactly how it is split.

ZIP codes partly in Mercer County

This ZIP code lies mostly in a neighbouring county but covers a twentieth or more of Mercer County.

Map of Mercer County ZIP codes

646326466164673

The ZIP codes of Mercer County, shaded. Outlines are Census ZIP Code Tabulation Areas (2020), which approximate the mail routes; PO-box and single-address codes have no area and are not drawn. Click any area to open its ZIP code.

Mercer County in numbers

About 3,482 people live in Mercer County, in 1,302 households, the 114th most populous of Missouri's 115 counties. The median household income is $62,679 a year, 11% below the Missouri median of $70,702 (US: $80,734). The median owner-occupied home is valued at $104,900 (54% below the Missouri median), and median gross rent is $590 a month. The median age is 42.4; 18.1% of adults 25 and over hold a bachelor's degree or higher (32.4% across Missouri); the average commute takes 23 minutes.

Population3,482Mercer3,482
Households1,302Mercer1,302
Median age42.4Mercer42.4Missouri39.0US 38.9
Median household income$62,679Mercer$62,679Missouri$70,702US $80,734
Median home value$104,900Mercer$104,900Missouri$230,300US $332,700
Median gross rent$590Mercer$590Missouri$1,033US $1,413
Bachelor's degree or higher18.1%Mercer18.1%Missouri32.4%US 35.7%
Mean commute22.6 minMercer22.6 minMissouri23.5 minUS 26.4 min
Population density8 / sq miMercer8 / sq mi

U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates. Survey estimates carry margins of error, wider for small places. Sources and methods.

Largest towns in Mercer County

Largest towns in Mercer County
TownZIP codesPopulation
Princeton 1 1,352
Mercer 1 325
Cainsville 1 212

Population of the census place of that name where there is one, otherwise of the ZIP codes the Postal Service addresses by it. A town's ZIP codes can reach past the county line.

Neighbouring counties

Counties that share a ZIP code with Mercer County.

Not sure you are in Mercer County? What county am I in? answers from your location, near a county line included.

Every ZIP code in Mercer County, with figures

ZIP codes in Mercer County
ZIP City Type Population Median income Median home
64632 Cainsville , MO Standard 371 $50,313 $79,600
64661 Mercer , MO Standard 757 $54,122 $73,800
64673 Princeton , MO Standard 2,497 $61,364 $101,600

Cite this page

zipcodes.pro. “Mercer County ZIP codes.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/state/mo/county/mercer

Underlying data is public domain or openly licensed — sources, vintages and licences.