Total monthly cost of ownership
Cost to Own a Home in St. Mary's County, Maryland
A $391,000 home here costs
$3,078per month, all in — with 20% down at today's 6.66% 30-year fixed rate.
A standard mortgage calculator would have told you $2,010. The real number is $1,068 higher every month — 53% more than the payment most buyers budget for.
Where every dollar goes
Only the first line is a mortgage payment. Change any assumption above and every figure below recalculates.
How St. Mary's County compares
St. Mary's County ranks 1,496th of 3,133 US counties by effective property tax rate, meaning property taxes here are lower than in 1,637 counties and higher than in 1,495. Within Maryland it ranks 19th of 24.
The numbers behind this page
| Measure | St. Mary's County | Source |
|---|---|---|
| Median home value | $390,900 | ACS B25077 |
| Median real estate taxes paid | $3,392 | ACS B25103 |
| Effective property tax rate | 0.868% | Derived |
| Median gross rent | $1,692 | ACS B25064 |
| Occupied housing units | 41,743 | ACS B25003 |
| Population | 114,372 | ACS B01003 |
| Residential electricity price | 21.77¢/kWh | EIA 5.6.A |
| 30-year fixed mortgage rate | 6.66% | Freddie Mac PMMS |
Other counties in Maryland
Compare the cost of the same home elsewhere in the state.
Questions about owning here
What is the property tax rate in St. Mary's County?
The effective property tax rate in St. Mary's County, Maryland is 0.868% of home value per year. On the county's median home value of $390,900, that works out to about $3,392 annually, or $283 per month.
How much does it cost to own a home in St. Mary's County?
A $391,000 home in St. Mary's County, Maryland costs approximately $3,078 per month with 20% down at 6.66%. That breaks down as $2,010 principal and interest, $283 property tax, $196 insurance, $264 utilities and $326 set aside for maintenance.
Why is this higher than the payment my lender quoted?
Lender quotes usually show principal and interest only, and sometimes property tax and insurance. They almost never include electricity, water or a maintenance reserve. Here those add about $590 a month, which is why the real cost is 53% above the mortgage payment alone.
Is it cheaper to rent in St. Mary's County?
Median gross rent in St. Mary's County, Maryland is $1,692 per month, compared with $3,078 to own the median home outright. Renting is cheaper month to month, though rent does not build equity and is not fixed for 30 years.
How much is the electric bill in St. Mary's County?
Maryland residential electricity averages 21.77¢ per kWh. At the US average household usage of 899 kWh per month, that is about $196. Actual bills vary considerably with house size, insulation and climate.
Sources & methodology
- Median home value, real estate taxes paid, gross rent, occupied units and population — US Census Bureau, American Community Survey ACS 2023 5-Year, tables B25077, B25103, B25064, B25003, B01003.
- Effective property tax rate — median real estate taxes paid divided by median home value.
- Mortgage rate — Freddie Mac PMMS, updated weekly.
- Residential electricity price — US Energy Information Administration, Electric Power Monthly, Table 5.6.A.
- Homeowners insurance (0.60%/yr), maintenance (1%/yr) and water and sewer ($68/mo) are modelled national estimates, not quoted figures. Every one is editable above.