Tax Equivalent Yield Calculator
Enter a tax-free bond yield and your marginal tax rates to instantly see the taxable equivalent yield: the return a fully taxable bond would have to offer to match your tax-free investment after taxes. The calculator handles federal-only, state-only, and doubly exempt bonds, and auto-fills your federal bracket from your taxable income and filing status.
What is tax equivalent yield?
Tax equivalent yield (TEY) is the pre-tax return a taxable bond would have to offer for an investor to be equally well off as holding a tax-exempt bond. Because municipal bond interest is excluded from federal income tax (and often state income tax for in-state bonds), investors in higher brackets can accept a lower nominal yield from a muni and still come out ahead after tax. TEY lets you put the two on the same footing. The formula is: TEY = tax-free yield / (1 - marginal tax rate). For example, if your federal bracket is 32% and you are looking at a 4.5% muni, the TEY is 4.5% / (1 - 0.32) = 6.618%. Any taxable bond yielding less than 6.618% is a worse after-tax choice.
Federal-only vs doubly exempt bonds
Most municipal bonds escape federal income tax. Whether they also escape state income tax depends on where the bond was issued and where you live. If you buy a muni issued by your home state (or a U.S. territory such as Puerto Rico), interest is typically also free from state income tax. For those doubly exempt bonds, you should use the combined federal-plus-state marginal rate in the TEY formula. The combined rate is not simply federal + state added together; instead it is: combined rate = federal + state - (federal x state). This reflects that state taxes are deducted from federal taxable income for itemizers, though for simplicity many practitioners use the additive approximation. Our calculator uses the precise formula. For a 32% federal and 6% state bracket, the combined rate is 0.32 + 0.06 - 0.32 x 0.06 = 36.08%, and TEY on a 4.5% muni becomes 7.04%.
Who benefits most from tax-free bonds?
The higher your marginal tax rate, the more valuable tax exemption is. Investors in the 10% or 12% bracket get a small uplift from munis; investors in the 32%, 35%, or 37% bracket can find munis delivering 6% to 7% equivalent taxable yields from bonds that nominally yield only 4% to 5%. That is why institutional holders of municipal bonds are dominated by high-income individuals, banks, and insurance companies. Investors in lower brackets often find that high-quality taxable bonds, Treasuries, or FDIC-insured CDs offer better risk-adjusted after-tax returns than munis, because muni prices already reflect the demand from high-bracket investors. If you live in a high-tax state such as California (13.3% top rate), New York (10.9%), or New Jersey (10.75%), the state tax exemption for in-state munis adds further value on top of the federal exemption.
How to use this calculator in practice
Start by entering the yield shown on the municipal bond or municipal bond fund you are considering. Enter your taxable income and filing status to auto-fill your 2026 federal bracket, or type your rate directly if you already know it. Indicate whether the bond is exempt from state tax (in-state bonds usually are), and enter your state marginal rate if relevant. If you want a dollar figure, enter the amount you plan to invest. The calculator gives you the TEY: compare it directly to yields on Treasuries, investment-grade corporate bonds, or CDs with a similar maturity and credit quality. Treasuries are federal-taxable but state-exempt, so when comparing munis to Treasuries you only need to use the federal rate. When comparing to fully taxable instruments, use the combined rate.
2026 Federal income tax brackets
| Bracket | Single: up to | MFJ: up to | TEY on a 4.5% muni (single) |
|---|---|---|---|
| 10% | $11,925 | $23,850 | 5.000% |
| 12% | $48,475 | $96,950 | 5.114% |
| 22% | $103,350 | $206,700 | 5.769% |
| 24% | $197,300 | $394,600 | 5.921% |
| 32% | $250,525 | $501,050 | 6.618% |
| 35% | $626,350 | $751,600 | 6.923% |
| 37% | Above | Above | 7.143% |
Marginal rates for single filers and married filing jointly (MFJ) under 2026 law.
Frequently asked questions
What is the tax equivalent yield formula?
Tax equivalent yield = tax-free yield / (1 - combined marginal tax rate). The combined marginal rate is your federal rate alone when the bond is federally exempt only, or federal + state - (federal x state) when it is also state-exempt. For example, a 4.5% muni and a 32% federal bracket gives TEY = 4.5% / (1 - 0.32) = 6.618%.
Is municipal bond interest always tax-free?
Municipal bond interest is generally exempt from federal income tax, but there are exceptions. Private activity bonds (PABs) may be subject to the Alternative Minimum Tax (AMT). Interest is also usually exempt from state and local tax only when the issuer is your home state or a U.S. territory such as Puerto Rico, Guam, or the U.S. Virgin Islands. Always verify the specific tax treatment of any bond you are considering.
How does state tax affect the comparison?
If the municipal bond is also exempt from your state income tax, you should use the combined federal-plus-state marginal rate, which increases the TEY. The combined rate is calculated as: federal + state - (federal x state). For a 24% federal and 5% state rate, the combined rate is 24% + 5% - (24% x 5%) = 27.8%, not 29%. Using 29% would slightly overstate the benefit.
Should I compare munis to Treasuries or corporate bonds?
Treasuries are federal-taxable but state-exempt, so when you compare a muni to a Treasury you should use only your federal tax rate in the TEY formula. Corporate bonds are fully taxable at both federal and state levels, so use the full combined rate. CD interest is also fully taxable, so use the combined rate there too.
Why does TEY matter more for high-income investors?
TEY scales with your marginal rate. At 12%, a 4.5% muni is equivalent to only 5.11% taxable. At 37%, the same muni is equivalent to 7.14% taxable. Because market prices for municipal bonds reflect strong demand from high-bracket investors, munis are typically priced so their nominal yields are already lower than comparable taxable bonds. They only become genuinely attractive once your bracket is high enough that the TEY surpasses what taxable instruments are offering.
Does capital gain on a muni sale affect TEY?
This calculator covers the yield component only. Capital gains from selling a municipal bond before maturity are fully taxable at your capital gains rate, the same as gains on stocks or taxable bonds. The tax advantage of munis applies to interest income, not to appreciation. If you expect to trade bonds actively, factor in potential capital gains exposure separately.