What Is Tax-Equivalent Yield?

When comparing bonds, the interest rate you see is not always the return you actually keep. Taxes can reduce the income you receive from a taxable bond, while certain tax-exempt investments may provide income that is partially or fully exempt from specific taxes.

A Tax-Equivalent Yield Calculator helps you make a more meaningful comparison. It estimates the taxable bond yield you would need to earn a similar return to a tax-free bond after considering your tax rate.

This can be especially useful when comparing municipal bonds or other tax-exempt investments with taxable bonds, certificates of deposit, and other fixed-income options.

How Does a Tax-Equivalent Yield Calculator Work?

The calculator uses your tax-free bond yield and applicable tax rate to estimate the equivalent taxable yield.

The basic formula is:

Tax-Equivalent Yield = Tax-Free Yield ÷ (1 − Tax Rate)

For example, suppose a tax-free bond offers a 4% yield, and your marginal tax rate is 25%.

The calculation would be:

4% ÷ (1 − 0.25) = 5.33%

This means a taxable bond would need to offer approximately a 5.33% yield to provide the same after-tax income as a 4% tax-free yield, assuming the simplified tax assumptions used by the calculator.

Why Compare Tax-Free and Taxable Bonds?

A taxable bond may appear more attractive because it offers a higher stated yield. However, part of that interest may be owed in taxes.

For example, a taxable bond yielding 5.5% may not actually provide 5.5% of spendable income if the interest is subject to your marginal tax rate.

A tax-free bond with a lower stated yield could potentially produce a comparable or higher after-tax return.

That is why looking at after-tax yield, rather than only the advertised yield, can provide a better basis for comparing fixed-income investments.

How to Calculate Tax-Equivalent Yield

Calculating tax-equivalent yield is relatively simple.

First, determine the yield of the tax-free investment. Then determine your applicable marginal tax rate. Finally, divide the tax-free yield by one minus the tax rate.

For example:

• Tax-free bond yield: 4%
• Marginal tax rate: 24%
• Tax-equivalent yield: 4% ÷ (1 − 0.24)
• Estimated equivalent taxable yield: 5.26%

In this example, a taxable investment would need to earn roughly 5.26% to produce a similar after-tax yield under the simplified calculation.

Tax-Equivalent Yield vs. After-Tax Yield

These two concepts are related but answer different questions.

Tax-equivalent yield tells you how much a taxable investment would need to earn to match the yield of a tax-free investment.

After-tax yield tells you how much of a taxable investment's stated return remains after applying the relevant tax rate.

For example, if a taxable bond earns 6% and your applicable tax rate is 25%, the simplified after-tax yield would be:

6% × (1 − 0.25) = 4.5%

This makes it easier to compare the taxable bond with a tax-free investment offering a similar yield.

Tax-Free Bond vs. Taxable Bond

There is no single bond type that is automatically better for every investor. The right choice depends on factors such as your tax situation, investment goals, risk tolerance, bond quality, maturity, liquidity, and expected return.

A tax-free bond with a lower stated yield may be attractive to an investor in a higher tax bracket. Meanwhile, a taxable bond with a higher yield may provide a better overall return for someone with a lower applicable tax rate.

Using a tax-equivalent yield calculator can help you compare these opportunities using the same after-tax perspective.

How Your Tax Rate Affects the Comparison

Your tax rate can have a significant impact on the tax-equivalent yield.

As the tax rate increases, the taxable yield required to match a tax-free investment also increases.

For example, a 4% tax-free yield would have an approximate tax-equivalent yield of:

• At a 10% tax rate: 4.44%
• At a 20% tax rate: 5.00%
• At a 25% tax rate: 5.33%
• At a 30% tax rate: 5.71%
• At a 35% tax rate: 6.15%

This illustrates why the same tax-free bond can look more attractive to investors facing different marginal tax rates.

How to Use Our Tax-Equivalent Yield Calculator

Our calculator is designed to make bond yield comparison straightforward.

Enter the tax-free bond yield and taxable bond yield, then provide your applicable federal, state or regional, and local tax rates. You can also enter an investment amount to compare the estimated annual income.

The calculator provides:

• Tax-equivalent yield
• Taxable bond after-tax yield
• Tax-free annual income
• Taxable bond annual income after tax
• Combined tax rate
• Yield comparison chart
• Bond income comparison table
• Downloadable CSV results
• Print or save-as-PDF functionality

The graphical comparison makes it easier to see how the stated yields and after-tax yields differ.

Tax-Equivalent Yield for Municipal Bonds

The concept of tax-equivalent yield is commonly discussed when evaluating municipal bonds because some municipal bond interest may receive favorable tax treatment depending on the investor and the specific bond.

For example, an investor may compare a municipal bond yielding 4% with a corporate or government bond offering a higher stated yield. Instead of comparing the two percentages directly, the investor can calculate the taxable equivalent of the municipal bond yield.

However, tax treatment can vary by jurisdiction and by the specific investment. Some bonds may have different federal, state, or local tax considerations, so investors should verify the applicable rules before making an investment decision.

What Is a Good Tax-Equivalent Yield?

There is no universal "good" tax-equivalent yield.

A higher yield can look attractive, but yield should not be considered separately from risk. Credit quality, maturity, interest-rate risk, liquidity, inflation, fees, and the possibility of changes in market value can all affect the overall investment outcome.

The calculator is therefore best used as a comparison tool rather than as a way to determine whether a particular bond is a good investment.

Tax-Equivalent Yield and Investment Decisions

Comparing investments based only on their headline yields can sometimes give an incomplete picture.

For example, a taxable bond offering a 6% yield may initially look better than a tax-free bond yielding 4.5%. But after accounting for taxes, the difference may be much smaller than it appears.

Looking at tax-equivalent yield and after-tax yield can help investors evaluate fixed-income opportunities on a more comparable basis.

You should also consider the investment's risk, duration, credit quality, fees, liquidity, and your overall financial objectives before making a decision.

Frequently Asked Questions

What is a tax-equivalent yield?

Tax-equivalent yield is the taxable interest rate an investment would need to provide to match the after-tax return of a tax-free investment.

What is the tax-equivalent yield formula?

The commonly used formula is:

Tax-Equivalent Yield = Tax-Free Yield ÷ (1 − Tax Rate)

The result is an estimate based on the tax rate entered into the calculation.

Is a tax-free bond always better than a taxable bond?

No. The better option depends on your tax rate, the yields available, investment risk, fees, maturity, and other factors. A taxable bond can still provide a higher after-tax return in some situations.

How does tax rate affect tax-equivalent yield?

A higher tax rate generally increases the taxable yield required to match a tax-free investment. This is because a larger portion of taxable interest would otherwise be lost to taxes.

Can I use this calculator for municipal bonds?

Yes. The calculator can be useful for comparing a tax-exempt municipal bond yield with the equivalent taxable yield. However, actual municipal bond tax treatment can vary, so the result should be considered an estimate.

What is after-tax yield?

After-tax yield is the portion of a taxable investment's stated return that remains after accounting for the applicable tax rate.

Should I compare bond yields before or after taxes?

For investors subject to taxes on bond interest, comparing after-tax yields can provide a more useful picture of potential income. Tax-equivalent yield can help translate a tax-free yield into a comparable taxable yield.

Final Thoughts

A bond's advertised yield is only part of the picture. Taxes can have a meaningful effect on the income you actually keep, which is why comparing investments on an after-tax basis can be useful.

Our Tax-Equivalent Yield Calculator gives you a quick way to compare tax-free and taxable bond yields, estimate the equivalent taxable return, and see how your tax rate can affect potential investment income.

Use the results as a starting point for comparing fixed-income investments, and consider your complete financial situation, investment risk, and applicable tax rules before making an investment decision.

Disclaimer: This calculator is provided for educational and informational purposes only. Tax laws and the treatment of investment income vary by jurisdiction and individual circumstances. The calculations use simplified assumptions and should not be considered tax, financial, or investment advice. Consult a qualified tax or financial professional for advice specific to your situation.