What Is a Tax Equivalent Yield Calculator?
A tax equivalent yield calculator converts a tax-exempt municipal bond yield into the taxable yield required to produce similar after-tax income. This matters because municipal bonds often quote lower nominal yields than taxable bonds. The lower quoted yield can still be competitive when federal, state, or local tax savings are included.
The calculator is most useful when comparing fixed-income choices with similar maturity, credit quality, liquidity, and call features. It does not tell you which bond is safer or which investment is suitable. It answers a narrower question: after the tax assumptions you entered, what taxable yield would be needed to match the municipal income estimate?
How to Calculate Tax Equivalent Yield
Start with the municipal bond yield. If the bond is treated as in-state exempt, this calculator keeps the municipal yield unchanged for state and local tax. If the bond is treated as out-of-state, the calculator reduces the municipal yield by the entered state and local rate. It then divides that tax-adjusted municipal yield by one minus the combined taxable rate.
The taxable alternative is treated as fully taxable for federal, state, and local income tax. That is a useful default for corporate bonds and many CDs, but it is not perfect for every security. Treasury interest, for example, is generally exempt from state and local income tax, so a Treasury comparison may need different assumptions.
Worked Examples
High-bracket municipal comparison
A 3.50% in-state municipal bond with a 35% federal rate and 5% state rate has a taxable-equivalent yield near 5.83% when the taxable alternative faces the combined tax rate. A taxable bond yielding 5.20% may look higher before tax, but the after-tax comparison can favor the municipal income.
Out-of-state municipal comparison
A 3.80% out-of-state municipal bond can lose part of its advantage when 6% state tax and 1% local tax apply. In that case, the municipal after-tax yield is reduced before the taxable-equivalent yield is calculated, which can make a strong taxable alternative more competitive.
How to Read Municipal vs Taxable Yield
Use tax equivalent yield as a screening comparison, not as a complete investment decision. A municipal bond and a taxable bond can have different credit ratings, maturities, call schedules, price volatility, liquidity, and reinvestment risk. A higher after-tax yield is more meaningful when the securities are otherwise comparable.
Tax treatment can also vary. IRS guidance distinguishes tax-exempt interest, taxable municipal interest, market discount, and private activity bond issues. The Municipal Securities Rulemaking Board explains that municipal interest is often federally tax-exempt and may also be state or local tax-exempt. Those words matter: often and may are not the same as always.
Frequently Asked Questions
What is tax equivalent yield?
Tax equivalent yield is the taxable yield required to match the after-tax income of a tax-exempt investment, usually a municipal bond. It helps compare a lower quoted municipal yield with a higher quoted taxable bond, CD, Treasury, or money-market yield.
How do you calculate tax equivalent yield?
A simple formula is tax equivalent yield = tax-adjusted municipal yield / (1 - marginal tax rate). If the municipal bond is not exempt from state or local tax, first reduce the municipal yield by the applicable state and local rate before comparing it with the fully taxable alternative.
Should I include state tax in tax equivalent yield?
Yes, when state or local tax applies to either side of the comparison. An in-state municipal bond may be exempt from state tax, while an out-of-state municipal bond may not be. The calculator makes this assumption visible so the result does not silently overstate the municipal advantage.
Does a higher tax equivalent yield mean the municipal bond is better?
Not by itself. Tax equivalent yield compares income after tax, but it does not measure credit risk, call risk, interest-rate risk, liquidity, bond premium, fund expenses, or whether the bond fits your portfolio. Compare equivalent risk investments before drawing a conclusion.
Can municipal bond income be subject to AMT?
Some private activity municipal bonds can create alternative minimum tax exposure. Market discount, capital gains, and fund distributions can also create taxable items. This calculator is a planning worksheet and does not calculate AMT or security-specific tax treatment.
Is Treasury interest treated the same as corporate bond interest?
No. Treasury interest is generally subject to federal income tax but exempt from state and local income tax. This page uses a fully taxable alternative assumption for simplicity. If you are comparing a Treasury, set state and local rates to zero for the taxable side or use a more specialized Treasury comparison.