63366 ZIP Code, O Fallon, MO
63366 is a ZIP code in O Fallon, Missouri in St. Charles County. It covers 69 square miles of land. The closest ZIP codes are 63369, 63367 and 63376. 54,769 people live here in 20,967 households, which puts it among the most populous 1% of Missouri ZIP codes. With about 790 people per square mile it is lightly settled, and most homes are owner-occupied (82%). Median household income is $100,621, above the Missouri median of $70,702.
Quick facts
- Mailing city: O Fallon, MO
- County: St. Charles County
- Land area: 69 sq mi
- Population: 54,769
- Median household income: $100,621
- Carrier routes: 33 (21,505 homes)
Key figures
| Measure | Value |
|---|---|
| Residents | 54,769 |
| Households | 20,967 |
| Median household income | $100,621 |
| Income per person | $45,718 |
| Median age | 40.4 |
| Homeowners | 82.1% |
| Median home value | $304,500 |
| Median rent | $1,302 |
| Bachelor's degree or higher | 33.3% |
| Average commute (minutes) | 24.9 |
| Households with kids under 18 | 33.0% |
| Moved in the past year | 8.8% |
| Below the poverty line | 7.0% |
| Broadband internet | 94.6% |
| Speak a non-English language at home | 7.0% |
Household income
| % of households | Value |
|---|---|
| <$10K | 3.4% |
| $10–15K | 2.6% |
| $15–25K | 3.2% |
| $25–35K | 4.4% |
| $35–50K | 9.3% |
| $50–75K | 14.5% |
| $75–100K | 12.3% |
| $100–150K | 22.8% |
| $150–200K | 14.4% |
| $200K+ | 13.1% |
Age
| % of all residents | Value |
|---|---|
| <10 | 11.1% |
| 10–19 | 13.3% |
| 20–24 | 5.0% |
| 25–34 | 12.4% |
| 35–44 | 15.0% |
| 45–54 | 13.5% |
| 55–64 | 13.2% |
| 65–74 | 10.5% |
| 75+ | 6.0% |
Tenure
| % of housing units | Value |
|---|---|
| Owned, with mortgage | 58.6% |
| Owned outright | 21.5% |
| Rented | 17.3% |
| Vacant | 2.5% |
Type of building
| % of housing units | Value |
|---|---|
| Detached house | 76.0% |
| Townhome | 8.6% |
| 2–4 units | 2.4% |
| 5–19 units | 5.2% |
| 20+ units | 2.7% |
| Mobile / other | 5.0% |
Businesses in 63366
1,192 business establishments with 21,736 employees (ZIP Codes Business Patterns 2023).
- Construction: 173
- Retail Trade: 146
- Health Care and Social Assistance: 130
- Accommodation and Food Services: 119
- Other Services (except Public Administration): 113
- Finance and Insurance: 92
- Professional, Scientific, and Technical Services: 82
- Administrative and Support and Waste Management and Remediation Services: 76
EDDM carrier routes
63366 has 33 USPS carrier routes with 21,505 residential and 1,135 business mailboxes. Open the EDDM route map.
Carrier routes in 63366
63366 has 33 USPS carrier routes (10 city (C), 23 rural (R)) with 21,505 residential and 1,135 business mailboxes. Routes range from 301 homes (C012) to 936 homes (R011); the median route has 649 homes. The Census counted 20,967 households in 63366 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.
| Homes per route | Routes |
|---|---|
| 1–249 | 0 |
| 250–499 | 3 |
| 500–749 | 21 |
| 750–999 | 9 |
| 1,000–1,499 | 0 |
| 1,500+ | 0 |
Best routes in 63366 for…
Most businesses
For B2B offers: office supplies, cleaning, IT, catering and commercial services.
- Route R040 — USPS business mailboxes 149, 683 homes
- Route R058 — USPS business mailboxes 136, 649 homes
- Route R020 — USPS business mailboxes 123, 363 homes
- Route C007 — USPS business mailboxes 117, 830 homes
- Route C005 — USPS business mailboxes 99, 507 homes
Select these 5 routes on the route map
Every carrier route in 63366
| Route | Type | Homes | Businesses | Est. median income | Est. owners | Est. families with kids | Est. moved in past year |
|---|---|---|---|---|---|---|---|
| C001 | City | 341 | 1 | $60,461 | — | — | — |
| C003 | City | 555 | 22 | $52,912 | — | — | — |
| C004 | City | 666 | 31 | $89,647 | — | — | — |
| C005 | City | 507 | 99 | $128,973 | — | — | — |
| C006 | City | 583 | 3 | $56,294 | — | — | — |
| C007 | City | 830 | 117 | $53,616 | — | — | — |
| C008 | City | 529 | 19 | $52,912 | — | — | — |
| C010 | City | 648 | 17 | $122,832 | — | — | — |
| C011 | City | 632 | 24 | $100,628 | — | — | — |
| C012 | City | 301 | 92 | $52,912 | — | — | — |
| R002 | Rural | 677 | 4 | $72,091 | — | — | — |
| R003 | Rural | 641 | 5 | $161,868 | — | — | — |
| R005 | Rural | 564 | 10 | $128,647 | — | — | — |
| R006 | Rural | 776 | 68 | $74,154 | — | — | — |
| R011 | Rural | 936 | 15 | $53,616 | — | — | — |
| R012 | Rural | 662 | 2 | $127,337 | — | — | — |
| R014 | Rural | 687 | 3 | $163,446 | — | — | — |
| R020 | Rural | 363 | 123 | $147,045 | — | — | — |
| R023 | Rural | 612 | 7 | $108,011 | — | — | — |
| R024 | Rural | 765 | 0 | $108,011 | — | — | — |
| R029 | Rural | 721 | 6 | $116,637 | — | — | — |
| R032 | Rural | 932 | 3 | $95,888 | — | — | — |
| R037 | Rural | 644 | 28 | $99,870 | — | — | — |
| R039 | Rural | 762 | 0 | $108,653 | — | — | — |
| R040 | Rural | 683 | 149 | $55,261 | — | — | — |
| R044 | Rural | 759 | 11 | $112,742 | — | — | — |
| R050 | Rural | 632 | 13 | $161,868 | — | — | — |
| R053 | Rural | 784 | 6 | $100,048 | — | — | — |
| R058 | Rural | 649 | 136 | $107,897 | — | — | — |
| R059 | Rural | 591 | 61 | $55,261 | — | — | — |
| R069 | Rural | 600 | 6 | $147,225 | — | — | — |
| R071 | Rural | 790 | 11 | $130,815 | — | — | — |
| R078 | Rural | 683 | 43 | $131,578 | — | — | — |
Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 63366 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
- 63369 — Old Monroe city, MO (6.2 mi)
- 63367 — Lake St. Louis city, MO (6.9 mi)
- 63376 — St. Peters city, MO (7.2 mi)
- 63368 — O'Fallon city, MO (7.3 mi)
- 63385 — Wentzville city, MO (8.2 mi)
- 62036 (8.4 mi)
- 63389 — Winfield city, MO (10.2 mi)
- 62013 — Brussels village, IL (10.6 mi)
Areas that include 63366
- O'Fallon, MO ZIP codes — 3 ZIP codes
- St. Paul, MO ZIP codes — 1 ZIP code
- St. Charles County ZIP codes — 14 ZIP codes
- Missouri ZIP code data
Where it ranks
- No. 5 of 11: lowest median age in St. Charles County
- No. 5 of 11: fastest population growth in St. Charles County
Mail every home in 63366
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) 63366, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.
Frequently asked questions
- What city is 63366 in?
- 63366 is a O Fallon, MO mailing address. By land area, 23% lies inside O'Fallon and 10% lies inside St. Paul; the rest is outside any Census-defined city or community.
- What county is 63366 in?
- 63366 is in St. Charles County.
- What is the population of 63366?
- About 54,769 people (±1,913), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 53,861.
- What is the median household income in 63366?
- $100,621 (±$6,872), compared with $70,702 for Missouri as a whole. Half the households in the ZIP code earn more and half earn less.
- How many carrier routes and mailboxes are in 63366?
- 33 USPS carrier routes with 21,505 residential and 1,135 business mailboxes (22,640 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
- What ZIP codes are near 63366?
- The closest, measured center to center: 63369 (6.2 mi, Old Monroe), 63367 (6.9 mi, Lake St. Louis), 63376 (7.2 mi, St. Peters), 63368 (7.3 mi, O'Fallon), 63385 (8.2 mi, Wentzville) and 62036 (8.4 mi).
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.