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Refinancing a mortgage in Port Costa, California

The typical owner-occupied home in Port Costa is worth about $600,000, 18% below the California median of $734,700 and 80% above the national median of $332,700. Owners pay a median $5,979 a year in property taxes, about 1.00% of their home's value, higher than the California rate of 0.70%. The median household earns $38,929 a year, so the median home costs 15.4 times the median income (7.4 times for California). 56% of occupied homes here are lived in by their owners, and 62% of those owners still have a mortgage.

Port Costa at a glance

Port Costa California U.S.
Median home value $600,000 $734,700 $332,700
Median property tax paid per year $5,979 $5,124 $3,119
Property tax as a share of value 1.00% 0.70% 0.94%
Median household income $38,929 $99,122 $80,734
Homes lived in by their owners 56% 56% 65%
Owner homes with a mortgage 62% 67% 61%
Median monthly costs, owners with a mortgage $2,925 $2,946 $1,963
Those costs as a share of the owners' income 48.5% 24.8% 21.0%
Median rent – $2,036 $1,413
Median year homes were built 1938 1976 1980
Vacant homes 0.0% 7.5% 10.1%
Population 296 39,287,377 334,922,499

What refinancing could save in Port Costa

Port Costa owners with a mortgage pay a median $2,925 a month for their mortgage, taxes, insurance and utilities, about 48.5% of their household income.

Say you owe $360,000, about 60% of the median home value here, on a 30-year loan at 8.11%. Refinancing into a new 30-year loan at this week's average of 7.11% would cut principal and interest from $2,669 to $2,422, saving about $247 a month.

Closing costs often run 2% to 5% of the loan. At 3%, about $10,800, the savings would cover the costs in about 44 months, so refinancing pays off if you keep the home longer than that.

A 15-year loan at 6.45% would raise the payment to $3,126, but you'd pay $309,128 less interest than on the new 30-year loan.

The average 30-year rate is 0.87 percentage points higher than a year ago, when it was 6.24%.

Refinancing a $360,000 balance
Current loan at 8.11%, 30 years$2,669
New 30-year loan at 7.11%$2,422
New 15-year loan at 6.45%$3,126
Monthly savings with the new 30-year loan$247

Principal and interest only; taxes and insurance stay the same.

Change the numbers in the calculator

Questions about mortgage refinance in Port Costa

What is the median home value in Port Costa?

About $600,000 for owner-occupied homes, according to the Census Bureau's 2020–2024 American Community Survey.

How much are property taxes in Port Costa?

Homeowners pay a median $5,979 a year, which is about 1.00% of the median home value. Your bill depends on your home's assessed value and local rates.

When does refinancing make sense?

When the monthly savings repay your closing costs before you expect to sell or refinance again. This week's average rates are 7.11% for 30 years and 6.45% for 15 years.

More about Port Costa

Sources: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates; Freddie Mac Primary Mortgage Market Survey, week of November 12, 2026. Estimates for small places have wide margins of error. About our data