St. Louis County, MO vs San Mateo County, CA: Cost of Living Difference

St. Louis County, MO is cheaper than San Mateo County, CA for modeled annual cost of living. This comparison shows the yearly cost gap, salary needed to keep similar purchasing power, and the categories driving the difference.

Is it cheaper?

St. Louis County, MO is cheaper than San Mateo County, CA.

Cheaper cost of living

Cheaper place

St. Louis County, MOSpend $45,446 more per year.

Cost gap

Moving to San Mateo County, CA is estimated to cost $45,446 more per year.

AnnualSpend $45,446 more per year.

MonthlySpend $3,787 more per month.

Salary needed

$50,000 in St. Louis County, MO is about $97,075 in San Mateo County, CA.

Biggest drivers

Housing increases by $18,053 per year. No measured category is cheaper in San Mateo County, CA.

St. Louis County, MOSan Mateo County, CA
Equivalent salary in San Mateo County, CA
$97,075
+94.15% higher
Current salary: $50,000
Household: 1 adult · 0 children
Median Income in St. Louis County, MO: $108,392
Median Income in San Mateo County, CA: $184,583
annual living index in St. Louis County, MO 44.53%
annual living index in San Mateo County, CA 50.77%

This estimate matches your purchasing power (equivalent salary) when moving from St. Louis County, MO to San Mateo County, CA.

* Living index is estimated as (estimated annual total cost / area median annual income) * 100. A living index above 100% means modeled costs exceed median income.

Cost of Living Breakdown by Category

Category-by-category comparison

Annual costs are shown for the selected household. The difference column shows how much more or less the category costs in San Mateo County, CA compared with St. Louis County, MO.

CategorySt. Louis County, MOSan Mateo County, CAAnnual differenceMonthly impactDirection
Housing$12,328$30,381+$18,053(146.44%)+$1,504Higher in San Mateo County, CA
Taxes$9,210$25,053+$15,843(172.02%)+$1,320Higher in San Mateo County, CA
Other Costs$5,296$11,095+$5,799(109.5%)+$483Higher in San Mateo County, CA
Transport$11,710$14,301+$2,591(22.13%)+$216Higher in San Mateo County, CA
Healthcare$4,996$7,535+$2,539(50.82%)+$212Higher in San Mateo County, CA
Food$4,731$5,354+$623(13.17%)+$52Higher in San Mateo County, CA
Childcare$0$0$0(0%)$0About even

Why this comparison matters

These notes use the actual annual cost differences between St. Louis County, MO and San Mateo County, CA, so the page highlights the budget tradeoffs behind the total.

Affordability vs median income

Modeled annual costs equal about 44.5% of median family income in St. Louis County, MO and 50.8% in San Mateo County, CA. This matters because a cheaper county can still feel tight if typical local incomes are also lower.

Housing

Housing is $18,053 per year higher in San Mateo County, CA than in St. Louis County, MO. Housing usually behaves like a fixed monthly commitment, so this matters most for renters or buyers checking whether San Mateo County, CA changes their baseline budget.

Food

Food is $623 per year higher in San Mateo County, CA than in St. Louis County, MO. Food costs affect weekly cash flow, so even a smaller modeled gap in San Mateo County, CA can show up quickly for households that cook most meals at home.

Transportation

Transportation is $2,591 per year higher in San Mateo County, CA than in St. Louis County, MO. Transportation matters for commuters because driving distance, vehicle costs, and transit access can change how much of a salary is left after getting around San Mateo County, CA.

Healthcare

Healthcare is $2,539 per year higher in San Mateo County, CA than in St. Louis County, MO. Healthcare differences are useful for planning premiums and out-of-pocket exposure, especially if San Mateo County, CA changes provider networks or plan options.

Other necessities

Other necessities is $5,799 per year higher in San Mateo County, CA than in St. Louis County, MO. Other necessities cover everyday basics, so changes in San Mateo County, CA help explain the non-housing costs that can quietly add up month after month.

Childcare

Childcare is about the same in St. Louis County, MO and San Mateo County, CA, so this category is not a major driver of the modeled gap. Childcare is most important for households with children; in San Mateo County, CA, this line can swing the result even when housing or taxes look manageable.

Taxes

Taxes is $15,843 per year higher in San Mateo County, CA than in St. Louis County, MO. Taxes affect take-home pay, so the gap in San Mateo County, CA matters even if the headline salary looks similar before deductions.

Methodology and data vintage

WatchPennies uses county-level 2026 cost estimates from a 2025-2026 cost-data snapshot. The comparison includes housing, food, transportation, healthcare, childcare, other necessities, taxes, total cost, and median family income context when available.

Read the full methodology

Frequently asked questions

Which is cheaper, St. Louis County, MO or San Mateo County, CA?

St. Louis County, MO is cheaper than San Mateo County, CA by about $45,446 per year.

How much salary is needed in San Mateo County, CA?

A $50,000 salary in St. Louis County, MO is modeled as roughly equivalent to $97,075 in San Mateo County, CA for the selected household profile.

What costs are included in this St. Louis County, MO vs San Mateo County, CA comparison?

The comparison includes housing, food, transportation, healthcare, childcare, other necessities, taxes, total cost, and median family income context when available.

Is this comparison personalized financial advice?

No. WatchPennies comparisons are directional planning estimates based on county-level public datasets, not personalized financial, tax, housing, or relocation advice.

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Cost of living methodology and data sources