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California After-Tax Yield Calculator

What a savings account or CD keeps after California's income tax (1% to 13.3% in 2026) and federal tax, and whether a Treasury bill, which California can't tax, keeps more.

In California, a 4.5% APY keeps 3.09% after 22% federal and 9.3% state tax. A 4% Treasury bill, which California can't tax, keeps 3.12%, so the Treasury bill keeps 0.03% more.

Savings keeps, after tax
3.09%
Treasury bill keeps, after tax
3.12%
Better after tax
Treasury bill
Treasury yield that matches the APY
3.96%

California income tax brackets, 2026 (taxable income)

RateSingle filersMarried filing jointly
1.00%$0 to $11,079$0 to $22,158
2.00%$11,079 to $26,264$22,158 to $52,528
4.00%$26,264 to $41,452$52,528 to $82,904
6.00%$41,452 to $57,542$82,904 to $115,084
8.00%$57,542 to $72,724$115,084 to $145,448
9.30%$72,724 to $371,479$145,448 to $742,958
10.30%$371,479 to $445,771$742,958 to $891,542
11.30%$445,771 to $742,953$891,542 to $1,000,000
12.30%$742,953 to $1,000,000$1,000,000 to $1,485,906
13.30%Over $1,000,000Over $1,485,906

What a 4.50% APY keeps in California, by state bracket (22% federal bracket)

California rateSavings or CD keepsT-bill yield that matches it
1.00%3.46%4.44%
2.00%3.42%4.38%
4.00%3.33%4.27%
6.00%3.24%4.15%
8.00%3.15%4.04%
9.30%3.09%3.96%
10.30%3.05%3.91%
11.30%3.00%3.85%
12.30%2.96%3.79%
13.30%2.91%3.73%

How this calculator works

Bank interest (savings, money market and CDs) is ordinary income to California and to the IRS. After-tax yield = APY × (1 − federal rate − California rate − local rate).

Treasury bills, notes and bonds are taxed only federally: federal law bars states from taxing their interest (31 U.S.C. 3124). After-tax yield = T-bill yield × (1 − federal rate).

The California rates are its 2026 brackets as compiled by the Tax Foundation from state law. Choose the bracket your taxable income falls in; the calculator starts at the rate for a single filer with $75,000 of taxable income (9.30%).

What it assumes

  • Your marginal rates apply to all of the interest.
  • California has no widespread local income tax on interest.
  • It ignores the state tax deduction on your federal return, which matters only if you itemise and are under the SALT cap.

Questions people ask

Does California tax interest from savings accounts and CDs?

Yes. California taxes bank interest as ordinary income at 1% to 13.3% in 2026, on top of federal income tax.

Are Treasury bills taxable in California?

No. Interest on Treasury bills, notes, bonds and US savings bonds is exempt from California income tax by federal law. It is still taxed federally.

Is a T-bill or a CD better in California?

At California's 9.30% rate and a 22% federal bracket, a 4.50% CD keeps 3.09%, the same as a T-bill yielding 3.96%. A T-bill paying more than that keeps more.

Do Treasury money market funds avoid California tax?

California exempts the Treasury share of a fund's dividends only when at least half the fund's assets are US government obligations at each quarter's end; Treasury-only money market funds usually qualify.

Other states

Terms explained

Related calculators

  • After-Tax Yield CalculatorWhat a savings or CD rate keeps after federal and state income tax, and whether a Treasury bill, which is free of state tax, keeps more.
  • Savings CalculatorWhat a savings account grows to at an APY, with a deposit every month, year by year.
  • CD CalculatorWhat a certificate of deposit earns by maturity, and what you keep if you close it early and pay the penalty.

Sources

Updated by the RateHerald team. The maths is tested against worked examples; report a problem.