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County ZIP codes · Wisconsin · FIPS 55105

Rock County, WI ZIP Codes

Rock County, Wisconsin has 23 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 20 residential and 3 for PO boxes or a single organization. 13 of the residential ones lie mainly in Rock County and 7 mainly in a neighboring county; 11 cross the county line. Median household income ranges from $66,069 in 53190 (Whitewater) to $108,036 in 53521 (Brooklyn) (Census Bureau, ACS 2020-2024).

  • ACS2020-24
  • Census2020

Where are the ZIP codes of Rock County?

53114 · Darien: $73k53190 · Whitewater: $66k53501 · Afton: –53502 · Albany: $87k53505 · Avalon: $92k53511 · Beloit: $67k53520 · Brodhead: $75k53521 · Brooklyn: $108k53525 · Clinton: $79k53534 · Edgerton: $89k53536 · Evansville: $88k53537 · Footville: $60k53538 · Fort Atkinson: $83k53545 · Janesville: $74k53546 · Janesville: $76k53548 · Janesville: $77k53563 · Milton: $90k53576 · Orfordville: $64k53585 · Sharon: $75k53589 · Stoughton: $96k53538531905352053548535115353453546535895353653563535215352553502535455311453576535855350553114 · Darien: $73k53190 · Whitewater: $66k53501 · Afton: –53502 · Albany: $87k53505 · Avalon: $92k53511 · Beloit: $67k53520 · Brodhead: $75k53521 · Brooklyn: $108k53525 · Clinton: $79k53534 · Edgerton: $89k53536 · Evansville: $88k53537 · Footville: $60k53538 · Fort Atkinson: $83k53545 · Janesville: $74k53546 · Janesville: $76k53548 · Janesville: $77k53563 · Milton: $90k53576 · Orfordville: $64k53585 · Sharon: $75k53589 · Stoughton: $96k53538531905352053548535115353453546535895353653563535215352553502535455311453576535855350553114 · Darien: $73k53190 · Whitewater: $66k53501 · Afton: –53502 · Albany: $87k53505 · Avalon: $92k53511 · Beloit: $67k53520 · Brodhead: $75k53521 · Brooklyn: $108k53525 · Clinton: $79k53534 · Edgerton: $89k53536 · Evansville: $88k53537 · Footville: $60k53538 · Fort Atkinson: $83k53545 · Janesville: $74k53546 · Janesville: $76k53548 · Janesville: $77k53563 · Milton: $90k53576 · Orfordville: $64k53585 · Sharon: $75k53589 · Stoughton: $96k535385319053520535485351153534535465358953536535635352153525535025311453576
The residential ZIP codes of Rock County (whole outlines, including the parts in neighboring counties), shaded by median household income in national fifths (ACS 2020-2024). <$54.1k$98.1k+no figure

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are its ZIP codes?

The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $73,889 and $87,667.

They carry 18 postal town names.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).

All 20 residential ZIP codes in Rock County

13 ZIP codes lie mainly in Rock County; 7 more reach into it from a neighboring county and follow the first table.

Residential ZIP codes mainly in Rock County, largest first; "In this county" is the share of the ZIP's land in the county
In this county
53511 Beloit 48,701 424 $67k $174k 100%
53546 Janesville 29,867 368 $76k $239k 100%
53545 Janesville 24,703 1,098 $74k $221k 100%
53548 Janesville 19,916 266 $77k $235k 100%
53534 Edgerton 12,241 144 $89k $295k 52%
53563 Milton 11,280 168 $90k $294k 98%
53536 Evansville 9,547 107 $88k $305k 100%
53520 Brodhead 6,687 56 $75k $223k 53%
53525 Clinton 4,066 71 $79k $248k 95%
53576 Orfordville 2,131 68 $64k $225k 100%
53537 Footville 752 862 $60k $155k 100%
53505 Avalon 358 16 $92k $300k 100%
53501 Afton 165 361 – – 100%

Partly in Rock County

Residential ZIP codes mainly in another county that reach at least 1% into Rock County, by their share here
In this county
53190 Whitewater 20,499 157 $66k $265k 27%
53114 Darien 1,979 66 $73k $241k 24%
53521 Brooklyn 3,640 61 $108k $391k 8%
53585 Sharon 2,264 83 $75k $200k 5%
53589 Stoughton 19,550 230 $96k $341k 2%
53538 Fort Atkinson 18,813 194 $83k $246k 2%
53502 Albany 2,393 46 $87k $252k 2%

Download the 23 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).

Which ZIP codes cross the county line?

11 ZIP codes of Rock County extend into another county. A ZIP code follows mail routes, not county borders.

Share of each ZIP code's land in Rock County and in the neighboring counties
ZIPIn RockElsewhere
5319027%Walworth County 49%; Jefferson County 24%
535892%Dane County 98%
535382%Jefferson County 98%
5353452%Dane County 43%; Jefferson County 5%
5356398%Jefferson County 2%
5352053%Green County 47%
5352595%Walworth County 5%
535218%Green County 50%; Dane County 41%
535022%Green County 98%
535855%Walworth County 95%
5311424%Walworth County 76%

Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).

PO Box and single-organization ZIP codes

ZIP codes in Rock County without a residential area (GeoNames postal codes)
ZIPPostal name
53512Beloit
53542Hanover
53547Janesville

Source: GeoNames postal codes (CC BY 4.0).

Which first three digits do Rock County's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Rock County's ZIP codes use 2 prefixes: 531 and 535.

Three-digit prefixes of Rock County's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Rock County's
PrefixSectional centerHereAll codes
531 Milwaukee, WI (SCF 530) 2 66
535 Madison, WI (SCF 535) 21 87

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.