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After-Tax Rate Compare.

Which account wins for your money? Enter your state, income, amount, and time horizon — we'll rank HYSAs, CDs, T-Bills, and money market funds after federal and state tax. Educational only, not financial advice.

Your state AK AL AR AZ CA CO CT DC DE FL GA HI IA ID IL IN KS KY LA MA MD ME MI MN MO MS MT NC ND NE NH NJ NM NV NY OH OK OR PA RI SC SD TN TX UT VA VT WA WI WV WY

Household income Under $75K $75K – $120K $120K – $180K $180K – $250K $250K+

Amount (USD)

Time horizon 3 months 6 months 12 months 2 years

Age (optional — powers the percentile benchmark) Prefer not to say Under 30 30–44 45–59 60–69 70+

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How the math works

Every savings vehicle's real return is its rate minus the tax on the interest. The tax varies by vehicle:

• HYSA / CD: federal income tax + state income tax on every dollar of interest.
• T-Bill: federal only — Treasury interest is exempt from state and local income tax.
• Government MMF (SPAXX, VUSXX): federal + roughly 20% of the state portion (the rest is Treasury-derived and state-exempt).

That state-tax exemption is the reason T-Bills can beat higher-APY HYSAs in California, New York, and other high-tax states — and why the answer changes depending on where you live.

What this doesn't model

This calculator uses top available rates and top marginal tax rates. It doesn't model AMT, NIIT (3.8% on investment income above $250K MFJ), state tax deductibility against federal, or early-withdrawal penalties on CDs. For amounts over $200K or edge cases, consult a tax professional.