What city is 80305 in?

80305 is a Boulder, CO mailing address. By land area, 68% lies inside Boulder and 2% lies inside Eldorado Springs; the rest is outside any Census-defined city or community.

What is the population of 80305?

About 16,291 people (±937), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 17,283.

What is the median household income in 80305?

$126,107 (±$10,372), compared with $95,470 for Colorado as a whole. Half the households in the ZIP code earn more and half earn less.

How many carrier routes and mailboxes are in 80305?

16 USPS carrier routes with 7,285 residential and 203 business mailboxes (7,488 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.

What ZIP codes are near 80305?

The closest, measured center to center: 80310 (2 mi, Boulder), 80303 (2.1 mi, Boulder), 80025 (4.5 mi, Eldorado Springs), 80027 (5.1 mi, Louisville), 80304 (5.1 mi, Boulder) and 80301 (5.4 mi, Boulder).

80305 ZIP Code, Boulder, CO

80305 is a ZIP code in Boulder, Colorado in Boulder County. It covers 5.8 square miles of land. The closest ZIP codes are 80310, 80303 and 80025. 16,291 people live here in 6,976 households. At about 2,799 people per square mile it has suburban density, and owners and renters are mixed (60% own). Median household income is $126,107, above the Colorado median of $95,470; 21% of residents moved in during the past year.

Quick facts

Mailing city: Boulder, CO
County: Boulder County
Land area: 5.8 sq mi
Population: 16,291
Median household income: $126,107
Carrier routes: 16 (7,285 homes)

Key figures

Measure	Value
Residents	16,291
Households	6,976
Median household income	$126,107
Income per person	$74,287
Median age	36.7
Homeowners	60.2%
Median home value	$1,032,900
Median rent	$2,311
Bachelor's degree or higher	79.4%
Average commute (minutes)	18.8
Households with kids under 18	24.0%
Moved in the past year	21.1%
Below the poverty line	12.2%
Broadband internet	95.6%
Speak a non-English language at home	12.0%

Household income

% of households	Value
<$10K	5.9%
$10–15K	2.7%
$15–25K	5.4%
$25–35K	3.5%
$35–50K	6.2%
$50–75K	10.4%
$75–100K	6.7%
$100–150K	15.7%
$150–200K	12.2%
$200K+	31.2%

Age

% of all residents	Value
<10	7.2%
10–19	13.4%
20–24	13.1%
25–34	14.4%
35–44	11.6%
45–54	13.4%
55–64	11.3%
65–74	9.6%
75+	6.0%

Tenure

% of housing units	Value
Owned, with mortgage	37.7%
Owned outright	20.2%
Rented	37.7%
Vacant	4.4%

Type of building

% of housing units	Value
Detached house	62.8%
Townhome	9.4%
2–4 units	4.1%
5–19 units	9.2%
20+ units	13.2%
Mobile / other	1.3%

Businesses in 80305

469 business establishments with 2,985 employees (ZIP Codes Business Patterns 2023).

Professional, Scientific, and Technical Services: 163
Health Care and Social Assistance: 68
Other Services (except Public Administration): 31
Retail Trade: 30
Construction: 28
Real Estate and Rental and Leasing: 26
Arts, Entertainment, and Recreation: 23
Accommodation and Food Services: 22

EDDM carrier routes

80305 has 16 USPS carrier routes with 7,285 residential and 203 business mailboxes. Open the EDDM route map.

Carrier routes in 80305

80305 has 16 USPS carrier routes (16 city (C)) with 7,285 residential and 203 business mailboxes. Routes range from 367 homes (C023) to 646 homes (C008); the median route has 442 homes. The Census counted 6,976 households in 80305 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per route	Routes
1–249	0
250–499	14
500–749	2
750–999	0
1,000–1,499	0
1,500+	0

Best routes in 80305 for…

Most businesses

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

Route C050 — USPS business mailboxes 58, 411 homes
Route C001 — USPS business mailboxes 40, 446 homes
Route C008 — USPS business mailboxes 35, 646 homes
Route C039 — USPS business mailboxes 25, 420 homes
Route C016 — USPS business mailboxes 10, 377 homes

Select these 5 routes on the route map

Every carrier route in 80305

Route	Type	Homes	Businesses	Est. median income	Est. owners	Est. families with kids	Est. moved in past year
C001	City	446	40	$129,169	—	—	—
C002	City	375	6	$108,070	—	—	—
C004	City	438	1	$200,001+	—	—	—
C005	City	483	0	$39,943	—	—	—
C008	City	646	35	$39,943	—	—	—
C009	City	465	9	$200,001+	—	—	—
C012	City	473	0	$156,864	—	—	—
C016	City	377	10	$150,166	—	—	—
C018	City	477	1	$200,001+	—	—	—
C023	City	367	4	$200,001+	—	—	—
C024	City	592	2	$126,073	—	—	—
C026	City	406	0	$126,073	—	—	—
C031	City	427	4	$200,001+	—	—	—
C039	City	420	25	$200,001+	—	—	—
C041	City	482	8	$78,068	—	—	—
C050	City	411	58	$200,001+	—	—	—

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 80305 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

80310 — Boulder city, CO (2 mi)
80303 — Boulder city, CO (2.1 mi)
80025 — Eldorado Springs CDP, CO (4.5 mi)
80027 — Louisville city, CO (5.1 mi)
80304 — Boulder city, CO (5.1 mi)
80301 — Boulder city, CO (5.4 mi)
80302 — Lazy Acres CDP, CO (6.3 mi)
80007 — Arvada city, CO (8.1 mi)

Areas that include 80305

Where it ranks

Mail every home in 80305

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) 80305, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 80305 in?: 80305 is a Boulder, CO mailing address. By land area, 68% lies inside Boulder and 2% lies inside Eldorado Springs; the rest is outside any Census-defined city or community.
What county is 80305 in?: 80305 is in Boulder County.
What is the population of 80305?: About 16,291 people (±937), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 17,283.
What is the median household income in 80305?: $126,107 (±$10,372), compared with $95,470 for Colorado as a whole. Half the households in the ZIP code earn more and half earn less.
How many carrier routes and mailboxes are in 80305?: 16 USPS carrier routes with 7,285 residential and 203 business mailboxes (7,488 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 80305?: The closest, measured center to center: 80310 (2 mi, Boulder), 80303 (2.1 mi, Boulder), 80025 (4.5 mi, Eldorado Springs), 80027 (5.1 mi, Louisville), 80304 (5.1 mi, Boulder) and 80301 (5.4 mi, Boulder).

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