51106 ZIP Code, Sioux City, IA

51106 is a ZIP code in Sioux City, Iowa in Woodbury County. It covers 33 square miles of land. The closest ZIP codes are 51105, 51101 and 51111. 28,592 people live here in 11,249 households, more than in 9 of every 10 Iowa ZIP codes. With about 854 people per square mile it is lightly settled, and most homes are owner-occupied (70%). Median household income is $78,434, close to the Iowa median of $75,059.

Quick facts

Key figures

MeasureValue
Residents28,592
Households11,249
Median household income$78,434
Income per person$39,145
Median age36.4
Homeowners70.2%
Median home value$200,200
Median rent$1,117
Bachelor's degree or higher28.6%
Average commute (minutes)15.3
Households with kids under 1829.5%
Moved in the past year7.8%
Below the poverty line13.6%
Broadband internet88.8%
Speak a non-English language at home12.1%

Household income

% of householdsValue
<$10K4.5%
$10–15K3.8%
$15–25K9.1%
$25–35K7.2%
$35–50K8.0%
$50–75K14.4%
$75–100K14.2%
$100–150K21.2%
$150–200K6.5%
$200K+11.0%

Age

% of all residentsValue
<1014.1%
10–1914.4%
20–247.6%
25–3412.8%
35–4411.4%
45–5412.3%
55–6410.9%
65–749.1%
75+7.4%

Tenure

% of housing unitsValue
Owned, with mortgage39.4%
Owned outright27.6%
Rented28.1%
Vacant5.0%

Type of building

% of housing unitsValue
Detached house73.7%
Townhome5.1%
2–4 units4.3%
5–19 units7.4%
20+ units6.6%
Mobile / other2.9%

Businesses in 51106

753 business establishments with 13,392 employees (ZIP Codes Business Patterns 2023).

EDDM carrier routes

51106 has 21 USPS carrier routes with 12,247 residential and 800 business mailboxes. Open the EDDM route map.

Carrier routes in 51106

51106 has 21 USPS carrier routes (17 city (C), 4 rural (R)) with 12,247 residential and 800 business mailboxes. Routes range from 250 homes (C033) to 833 homes (R009); the median route has 605 homes. The Census counted 11,249 households in 51106 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per routeRoutes
1–2490
250–4995
500–74914
750–9992
1,000–1,4990
1,500+0

Best routes in 51106 for…

Most businesses

For B2B offers: office supplies, cleaning, IT, catering and commercial services.

  1. Route C080 — USPS business mailboxes 257, 656 homes
  2. Route R005 — USPS business mailboxes 154, 435 homes
  3. Route C008 — USPS business mailboxes 91, 503 homes
  4. Route C081 — USPS business mailboxes 63, 746 homes
  5. Route C063 — USPS business mailboxes 40, 629 homes

Select these 5 routes on the route map

Every carrier route in 51106

RouteTypeHomesBusinessesEst. median incomeEst. ownersEst. families with kidsEst. moved in past year
C002City63613$83,957———
C005City61218$56,224———
C008City50391$56,787———
C012City52620$49,776———
C025City5774$116,326———
C029City6995$83,957———
C033City25018$59,365———
C037City60513$47,173———
C048City5771$54,954———
C059City4582$74,336———
C060City54619$78,704———
C063City62940$90,855———
C066City60611$90,855———
C074City7327$91,952———
C080City656257$53,311———
C081City74663$49,054———
C091City44018$78,704———
R002Rural37516$143,902———
R005Rural435154$75,000———
R007Rural80616$143,902———
R009Rural83314$75,000———

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 51106 on the EDDM route map.

How route demographics are estimated

Mailbox counts come from USPS; demographics are estimates

The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).

How a route gets its figures: the block-group length-share method

We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.

Margins of error

Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.

Different years

USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.

Why some routes show identical figures

Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.

Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.

Nearby ZIP codes

Areas that include 51106

Where it ranks

Mail every home in 51106

Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.

EDDM guides

ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 51106, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 51106 in?
51106 is a Sioux City, IA mailing address. By land area, 43% lies inside Sioux City; the rest is outside any Census-defined city or community.
What county is 51106 in?
51106 is in Woodbury County.
What is the population of 51106?
About 28,592 people (±1,320), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 28,655.
What is the median household income in 51106?
$78,434 (±$6,139), compared with $75,059 for Iowa as a whole. Half the households in the ZIP code earn more and half earn less.
How many carrier routes and mailboxes are in 51106?
21 USPS carrier routes with 12,247 residential and 800 business mailboxes (13,049 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 51106?
The closest, measured center to center: 51105 (4.1 mi, Sioux City), 51101 (4.6 mi, Sioux City), 51111 (5.1 mi, Sioux City), 51054 (5.8 mi, Sergeant Bluff), 51104 (6.7 mi, Sioux City) and 68776 (6.7 mi, South Sioux City).

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.