What does WatchPennies calculate?

WatchPennies estimates cost of living by US county across housing, food, transportation, healthcare, childcare, other necessities, taxes, and income context.

Do I need an account to use WatchPennies?

No. WatchPennies is a privacy-first web calculator that can be used without creating an account.

Can I compare two counties on WatchPennies?

Yes. WatchPennies lets you compare counties and adjust salary and family type to estimate relative cost differences.

What does the St. Louis County, MO vs Pima County, AZ comparison show?

It compares estimated living costs by category, including housing, food, transportation, healthcare, childcare, other necessities, taxes, and income context.

Can I change the salary and family type?

Yes. The comparison calculator supports salary and family type inputs so you can model costs for different households.

Does WatchPennies require an account for comparisons?

No. County comparisons are available without creating an account.

St. Louis County, MO vs Pima County, AZ: Cost of Living Difference

Is it cheaper?

Pima County, AZ is cheaper than St. Louis County, MO.

Moving to Pima County, AZ is estimated to save $3,852 per year.

Cheaper County

Pima County, AZSave about $3,852 per year.

Salary needed

$50,000 in St. Louis County, MO is about $46,010 in Pima County, AZ.

Biggest drivers

Transport increases by $343 per year. Taxes saves $1,563 per year.

Housing: $1,036 lower in Pima County, AZ

Taxes: $1,563 lower in Pima County, AZ

Childcare: about the same in both counties

Healthcare: $381 lower in Pima County, AZ

Food: $681 lower in Pima County, AZ

Transport: $343 higher in Pima County, AZ

St. Louis County, MO→Pima County, AZ

Equivalent salary in Pima County, AZ

$46,010

-7.98% lower

Current salary: $50,000

Household: 1 adult · 0 children

Median Income in St. Louis County, MO: $108,392

Median Income in Pima County, AZ: $87,639

Living Index in St. Louis County, MO 44.53%

Living Index in Pima County, AZ 50.69%

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

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

Cost of Living Breakdown by Category

Summary

Moving from St. Louis County, MO to Pima County, AZ is estimated to save $3,852 per year. A $50,000 salary in St. Louis County, MO would have similar purchasing power to about $46,010 in Pima County, AZ. The largest savings come from taxes and housing.

This is a 7.98% decrease in modeled annual costs. Taxes is $1,563 per year lower (16.97%); Housing is $1,036 per year lower (8.4%).

Below we break down the annual categories behind the difference using Economic Policy Institute 2026 Family Budget data.

What changed the most?

The following cards show the annual category differences that most affect the move to Pima County, AZ.

Biggest Cost

Largest annual cost increase when moving to Pima County, AZ

Annual Increase:

$343 per year

TRANSPORT has the largest annual increase when moving to Pima County, AZ.

Biggest Savings

Largest annual savings when moving to Pima County, AZ

Annual Savings:

$1,563 per year

TAXES has the largest annual savings when moving to Pima County, AZ.

Breakdown of price percentages per category.

Numbers are average costs per section.

Category	Difference
Housing	-8.40% lower
St. Louis County, MO Pima County, AZ Average Cost $12328.00 $11292.00 INFO: Housing costs are based on Department of Housing and Urban Development data. The estimate uses 40th percentile rent for privately owned rental units in each area. Studio apartments are paired with one-adult households, one-bedroom apartments with two-adult households, and two-bedroom apartments with households that have children.
Food	-14.39% lower
St. Louis County, MO Pima County, AZ Average Cost $4731.00 $4050.00 INFO: Food costs are based on the U.S. Department of Agriculture's food plans. Numbers are normalized to each area using Feeding America and Meal Gap data. This estimate assumes most food is bought at local grocery stores and prepared at home.
Transport	2.93% higher
St. Louis County, MO Pima County, AZ Average Cost $11710.00 $12053.00 INFO: Transportation costs are a combination of auto ownership, auto use, and public transit. Data is collected from the Center for Neighborhood Technology (CNT).
Healthcare	-7.63% lower
St. Louis County, MO Pima County, AZ Average Cost $4996.00 $4615.00 INFO: Healthcare expenses come from average insurance premiums and out-of-pocket costs. The estimate assumes families purchase the lowest-cost available insurance plan under the Affordable Care Act. Data comes from Kaiser Family Foundation and the U.S. Department of Health and Human Services (HHS).
Other Costs	-10.06% lower
St. Louis County, MO Pima County, AZ Average Cost $5296.00 $4763.00 INFO: This cost is calculated through the average spending of categories deemed necessary by the Bureau of Labor Statistics Consumer Expenditure Survey. These include apparel, personal care, household supplies, reading materials, and school supplies.
Childcare	0.00% higher
St. Louis County, MO Pima County, AZ Average Cost $0.00 $0.00 INFO: Childcare expenses are based on combined costs for center-based care and family-based care for 4-year-olds and school-aged children. For households with one child, the estimate assumes the child is 4 years old. For households with two children, the estimate assumes the second child is 8 years old.
Taxes	-16.97% lower
St. Louis County, MO Pima County, AZ Average Cost $9210.00 $7647.00 INFO: Taxes are calculated from the National Bureau of Economic Research. The number weighs in personal income tax, state income tax, federal Social Security, and Medicare taxes.

In Pima County, AZ, modeled annual costs are $44,420 compared with $48,272 in St. Louis County, MO.

Overall, annual costs are lower in Pima County, AZ. The category breakdown above shows where the move creates the most room in the budget.

In this case Pima County, AZ and St. Louis County, MO are both metropolitan locations.

Use our map to visually compare multiple counties at once.

Use the Cost of Living Map