What city is 80303 in?

80303 is a Boulder, CO mailing address. By land area, 18% lies inside Boulder, 8% lies inside Paragon Estates and 6% lies inside Eldorado Springs; the rest is outside any Census-defined city or community.

What is the population of 80303?

About 24,996 people (±1,327), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 25,328.

What is the median household income in 80303?

$78,555 (±$3,965), 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 80303?

20 USPS carrier routes with 12,581 residential and 705 business mailboxes (13,291 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.

What ZIP codes are near 80303?

The closest, measured center to center: 80305 (2.1 mi, Boulder), 80027 (3.1 mi, Louisville), 80310 (3.5 mi, Boulder), 80301 (5 mi, Boulder), 80025 (5.8 mi, Eldorado Springs) and 80026 (6.4 mi, Lafayette).

80303 ZIP Code, Boulder, CO

80303 is a ZIP code in Boulder, Colorado in Boulder County. It covers 22 square miles of land. The closest ZIP codes are 80305, 80027 and 80310. 24,996 people live here in 11,783 households. At about 1,142 people per square mile it has suburban density, and owners and renters are mixed (44% own). Median household income is $78,555, below the Colorado median of $95,470; the median age is 29.3, younger than most ZIP codes.

Quick facts

Mailing city: Boulder, CO
County: Boulder County
Land area: 22 sq mi
Population: 24,996
Median household income: $78,555
Carrier routes: 20 (12,581 homes)

Key figures

Measure	Value
Residents	24,996
Households	11,783
Median household income	$78,555
Income per person	$62,355
Median age	29.3
Homeowners	43.9%
Median home value	$961,900
Median rent	$1,910
Bachelor's degree or higher	80.1%
Average commute (minutes)	18.2
Households with kids under 18	13.2%
Moved in the past year	32.1%
Below the poverty line	23.1%
Broadband internet	94.8%
Speak a non-English language at home	15.5%

Household income

% of households	Value
<$10K	11.8%
$10–15K	3.0%
$15–25K	7.7%
$25–35K	8.4%
$35–50K	8.9%
$50–75K	8.4%
$75–100K	12.5%
$100–150K	11.1%
$150–200K	8.4%
$200K+	19.7%

Age

% of all residents	Value
<10	5.7%
10–19	12.2%
20–24	25.1%
25–34	13.4%
35–44	10.8%
45–54	9.4%
55–64	6.9%
65–74	7.5%
75+	8.9%

Tenure

% of housing units	Value
Owned, with mortgage	23.7%
Owned outright	17.0%
Rented	51.4%
Vacant	8.0%

Type of building

% of housing units	Value
Detached house	35.7%
Townhome	5.8%
2–4 units	5.6%
5–19 units	15.8%
20+ units	37.1%
Mobile / other	0.0%

Businesses in 80303

944 business establishments with 8,830 employees (ZIP Codes Business Patterns 2023).

Professional, Scientific, and Technical Services: 228
Health Care and Social Assistance: 157
Other Services (except Public Administration): 86
Real Estate and Rental and Leasing: 75
Retail Trade: 63
Finance and Insurance: 56
Accommodation and Food Services: 48
Construction: 46

EDDM carrier routes

80303 has 20 USPS carrier routes with 12,581 residential and 705 business mailboxes. Open the EDDM route map.

Carrier routes in 80303

80303 has 20 USPS carrier routes (17 city (C), 3 rural (R)) with 12,581 residential and 705 business mailboxes. Routes range from 360 homes (R001) to 1,425 homes (C004); the median route has 576 homes. The Census counted 11,783 households in 80303 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per route	Routes
1–249	0
250–499	8
500–749	7
750–999	3
1,000–1,499	2
1,500+	0

Best routes in 80303 for…

Most businesses

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

Route C027 — USPS business mailboxes 222, 680 homes
Route R003 — USPS business mailboxes 96, 363 homes
Route C015 — USPS business mailboxes 79, 400 homes
Route C021 — USPS business mailboxes 76, 752 homes
Route C051 — USPS business mailboxes 67, 704 homes

Select these 5 routes on the route map

Every carrier route in 80303

Route	Type	Homes	Businesses	Est. median income	Est. owners	Est. families with kids	Est. moved in past year
C004	City	1,425	5	$23,239	—	—	—
C006	City	577	6	$81,461	—	—	—
C010	City	543	6	$154,189	—	—	—
C011	City	1,153	17	$23,239	—	—	—
C015	City	400	79	$130,982	—	—	—
C017	City	453	1	$100,756	—	—	—
C021	City	752	76	$39,594	—	—	—
C022	City	845	7	$84,356	—	—	—
C025	City	381	0	$156,253	—	—	—
C027	City	680	222	$36,344	—	—	—
C030	City	629	9	$36,344	—	—	—
C033	City	422	2	$81,461	—	—	—
C034	City	574	6	$106,713	—	—	—
C040	City	700	2	$156,253	—	—	—
C043	City	385	4	$130,982	—	—	—
C051	City	704	67	$130,982	—	—	—
C052	City	779	54	$22,136	—	—	—
R001	Rural	360	43	—	—	—	—
R003	Rural	363	96	$155,751	—	—	—
R005	Rural	456	3	$130,982	—	—	—

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 80303 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

80305 — Boulder city, CO (2.1 mi)
80027 — Louisville city, CO (3.1 mi)
80310 — Boulder city, CO (3.5 mi)
80301 — Boulder city, CO (5 mi)
80025 — Eldorado Springs CDP, CO (5.8 mi)
80026 — Lafayette city, CO (6.4 mi)
80304 — Boulder city, CO (6.5 mi)
80007 — Arvada city, CO (7.4 mi)

Areas that include 80303

Boulder, CO ZIP codes — 6 ZIP codes
Paragon Estates, CO ZIP codes — 1 ZIP code
Eldorado Springs, CO ZIP codes — 2 ZIP codes
Boulder County ZIP codes — 21 ZIP codes
Colorado ZIP code data

Where it ranks

Mail every home in 80303

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) 80303, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 80303 in?: 80303 is a Boulder, CO mailing address. By land area, 18% lies inside Boulder, 8% lies inside Paragon Estates and 6% lies inside Eldorado Springs; the rest is outside any Census-defined city or community.
What county is 80303 in?: 80303 is in Boulder County.
What is the population of 80303?: About 24,996 people (±1,327), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 25,328.
What is the median household income in 80303?: $78,555 (±$3,965), 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 80303?: 20 USPS carrier routes with 12,581 residential and 705 business mailboxes (13,291 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 80303?: The closest, measured center to center: 80305 (2.1 mi, Boulder), 80027 (3.1 mi, Louisville), 80310 (3.5 mi, Boulder), 80301 (5 mi, Boulder), 80025 (5.8 mi, Eldorado Springs) and 80026 (6.4 mi, Lafayette).

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