About RungRate

Why this site exists

People parking an emergency fund or short-term savings face a genuinely confusing comparison. T-bills, CDs, and high-yield savings accounts quote rates in different conventions, mature on different schedules, and are taxed differently — Treasury interest skips state income tax entirely, while CD and savings interest does not. Forum threads are full of hand-built spreadsheets trying to answer the same question: after tax, in my state, which one actually pays more?

RungRate packages that math into tools anyone can use in a browser, with nothing hidden. Every calculator publishes its formula in plain text, walks through a worked example with real numbers, and links the data sources it draws from.

Our approach

• Show the work. Formulas appear on the page next to the tool, not buried in code. If you disagree with an assumption, you can see exactly which one.
• Date everything. Yields and tax rates change. Every table carries an as-of date and a named source so you know how fresh the inputs are.
• Stay neutral. RungRate does not sell financial products, take referral fees from banks or brokerages, or rank institutions. The tools compare instrument types, not vendors.
• Prefer primary sources. Treasury yields come from U.S. Treasury published data; deposit-rate benchmarks come from FDIC releases; state tax figures come from state revenue authorities. Details are on the methodology page.

What RungRate is not

This site is an educational reference, not a financial adviser. It does not know your tax bracket, filing status, cash needs, or risk situation, and its outputs are estimates built on stated assumptions. Nothing here is financial, tax, or investment advice, and figures should be verified with the issuing institution or a qualified professional before you act on them.

Contact and corrections

Spotted a stale rate, a broken formula, or a source that has moved? Corrections are welcome — see the contact page. Data corrections are prioritized over all other mail.