20678 ZIP Code, Prince Frederick, MD
20678 is a ZIP code in Prince Frederick, Maryland in Calvert County. It covers 45 square miles of land. The closest ZIP codes are 20676, 20612 and 20639. 12,752 people live here in 4,858 households. With about 284 people per square mile it is lightly settled, and most homes are owner-occupied (78%). Median household income is $125,732, above the Maryland median of $103,678.
Quick facts
- Mailing city: Prince Frederick, MD
- County: Calvert County
- Land area: 45 sq mi
- Population: 12,752
- Median household income: $125,732
- Carrier routes: 10 (5,113 homes)
Key figures
| Measure | Value |
|---|---|
| Residents | 12,752 |
| Households | 4,858 |
| Median household income | $125,732 |
| Income per person | $54,751 |
| Median age | 38.4 |
| Homeowners | 78.4% |
| Median home value | $455,100 |
| Median rent | $1,388 |
| Bachelor's degree or higher | 30.3% |
| Average commute (minutes) | 39.9 |
| Households with kids under 18 | 34.4% |
| Moved in the past year | 10.0% |
| Below the poverty line | 7.5% |
| Broadband internet | 91.6% |
| Speak a non-English language at home | 8.5% |
Household income
| % of households | Value |
|---|---|
| <$10K | 2.2% |
| $10–15K | 3.7% |
| $15–25K | 4.8% |
| $25–35K | 3.5% |
| $35–50K | 7.2% |
| $50–75K | 10.5% |
| $75–100K | 8.2% |
| $100–150K | 21.7% |
| $150–200K | 15.3% |
| $200K+ | 22.8% |
Age
| % of all residents | Value |
|---|---|
| <10 | 11.7% |
| 10–19 | 10.9% |
| 20–24 | 8.4% |
| 25–34 | 13.2% |
| 35–44 | 14.8% |
| 45–54 | 12.5% |
| 55–64 | 11.2% |
| 65–74 | 10.8% |
| 75+ | 6.4% |
Tenure
| % of housing units | Value |
|---|---|
| Owned, with mortgage | 62.4% |
| Owned outright | 11.4% |
| Rented | 20.0% |
| Vacant | 6.2% |
Type of building
| % of housing units | Value |
|---|---|
| Detached house | 76.4% |
| Townhome | 8.3% |
| 2–4 units | 1.2% |
| 5–19 units | 3.1% |
| 20+ units | 9.0% |
| Mobile / other | 2.0% |
Businesses in 20678
487 business establishments with 7,565 employees (ZIP Codes Business Patterns 2023).
- Health Care and Social Assistance: 90
- Retail Trade: 68
- Other Services (except Public Administration): 64
- Construction: 53
- Accommodation and Food Services: 52
- Professional, Scientific, and Technical Services: 36
- Finance and Insurance: 30
- Real Estate and Rental and Leasing: 20
EDDM carrier routes
20678 has 10 USPS carrier routes with 5,113 residential and 542 business mailboxes. Open the EDDM route map.
Carrier routes in 20678
20678 has 10 USPS carrier routes (9 rural (R), 1 highway contract (H)) with 5,113 residential and 542 business mailboxes. Routes range from 282 homes (H004) to 773 homes (R004); the median route has 528 homes. The Census counted 4,858 households in 20678 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.
| Homes per route | Routes |
|---|---|
| 1–249 | 0 |
| 250–499 | 5 |
| 500–749 | 4 |
| 750–999 | 1 |
| 1,000–1,499 | 0 |
| 1,500+ | 0 |
Best routes in 20678 for…
Most businesses
For B2B offers: office supplies, cleaning, IT, catering and commercial services.
- Route R002 — USPS business mailboxes 162, 334 homes
- Route R003 — USPS business mailboxes 105, 393 homes
- Route R004 — USPS business mailboxes 98, 773 homes
- Route R007 — USPS business mailboxes 82, 708 homes
- Route R006 — USPS business mailboxes 52, 486 homes
Select these 5 routes on the route map
Every carrier route in 20678
| Route | Type | Homes | Businesses | Est. median income | Est. owners | Est. families with kids | Est. moved in past year |
|---|---|---|---|---|---|---|---|
| H004 | Highway contract | 282 | 0 | $137,691 | — | — | — |
| R001 | Rural | 570 | 5 | $108,131 | — | — | — |
| R002 | Rural | 334 | 162 | $109,176 | — | — | — |
| R003 | Rural | 393 | 105 | $108,131 | — | — | — |
| R004 | Rural | 773 | 98 | $109,176 | — | — | — |
| R005 | Rural | 640 | 7 | $108,131 | — | — | — |
| R006 | Rural | 486 | 52 | $109,176 | — | — | — |
| R007 | Rural | 708 | 82 | $98,453 | — | — | — |
| R008 | Rural | 591 | 30 | $108,131 | — | — | — |
| R571 | Rural | 336 | 1 | $137,691 | — | — | — |
Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 20678 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
- 20676 — St. Leonard CDP, MD (3.8 mi)
- 20612 — Benedict CDP, MD (4.7 mi)
- 20639 — Huntingtown CDP, MD (5.3 mi)
- 20608 — Aquasco CDP, MD (6.9 mi)
- 20685 — St. Leonard CDP, MD (7.2 mi)
- 20615 — Broomes Island CDP, MD (8.2 mi)
- 20637 — Hughesville CDP, MD (8.7 mi)
- 20732 — Chesapeake Beach town, MD (9.4 mi)
Areas that include 20678
- Prince Frederick, MD ZIP codes — 1 ZIP code
- Calvert County ZIP codes — 13 ZIP codes
- Maryland ZIP code data
Where it ranks
- No. 3 of 12: lowest median age in Calvert County
- No. 5 of 11: fastest population growth in Calvert County
Mail every home in 20678
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) 20678, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.
Frequently asked questions
- What city is 20678 in?
- 20678 is a Prince Frederick, MD mailing address. By land area, 8% lies inside Prince Frederick; the rest is outside any Census-defined city or community.
- What county is 20678 in?
- 20678 is in Calvert County.
- What is the population of 20678?
- About 12,752 people (±926), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 12,818.
- What is the median household income in 20678?
- $125,732 (±$12,236), compared with $103,678 for Maryland as a whole. Half the households in the ZIP code earn more and half earn less.
- How many carrier routes and mailboxes are in 20678?
- 10 USPS carrier routes with 5,113 residential and 542 business mailboxes (5,657 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
- What ZIP codes are near 20678?
- The closest, measured center to center: 20676 (3.8 mi, St. Leonard), 20612 (4.7 mi, Benedict), 20639 (5.3 mi, Huntingtown), 20608 (6.9 mi, Aquasco), 20685 (7.2 mi, St. Leonard) and 20615 (8.2 mi, Broomes Island).
This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.