💡 Tip: Municipal bonds are typically exempt from federal income tax, and may be exempt from state tax if issued in your state of residence.
How to Use This Tool
Enter the yield of your tax-exempt investment (e.g., a municipal bond) as a percentage. Select your marginal federal income tax rate from the dropdown, or choose "Custom" to enter a specific rate. Add your marginal state tax rate if applicable (optional). Enter a taxable yield (e.g., a CD or corporate bond) if you want to compare returns directly. Click "Calculate" to see your tax equivalent yield and detailed breakdown. Use the "Reset" button to clear all inputs and start over.
All fields accept percentages as whole numbers or decimals (e.g., 3.5 for 3.5%). Inputs are validated to ensure they fall between 0 and 100%.
Formula and Logic
The core formula for Tax Equivalent Yield (TEY) is:
TEY = Tax-Exempt Yield / (1 - Marginal Tax Rate)
Marginal Tax Rate is the combined federal and state income tax rate you pay on your highest dollar of income, expressed as a decimal. For example, if your federal rate is 22% and state rate is 5%, your total marginal rate is 27% (0.27).
This formula calculates the taxable yield you would need to earn to match the after-tax return of a tax-exempt investment. Tax-exempt investments (like municipal bonds) are not subject to federal income tax, and may be exempt from state tax if issued in your state of residence.
After-tax yield for taxable investments is calculated as: Taxable Yield * (1 - Marginal Tax Rate)
Practical Notes
- Municipal bonds are most beneficial for investors in higher tax brackets: the higher your marginal tax rate, the more valuable tax-exempt yields become.
- Always verify if a municipal bond is subject to the Alternative Minimum Tax (AMT), as some are not fully tax-exempt.
- State tax rates only apply if the municipal bond is subject to state income tax. Bonds issued by your state of residence are typically exempt from both federal and state tax.
- Tax equivalent yield does not account for investment fees, commissions, or credit risk differences between taxable and tax-exempt investments.
- For joint filers, use the marginal tax rate for your combined income when selecting your federal tax bracket.
Why This Tool Is Useful
Comparing taxable and tax-exempt investments is rarely straightforward, as their tax treatments differ significantly. This tool eliminates guesswork by standardizing returns to a taxable equivalent, letting you make apples-to-apples comparisons between municipal bonds, certificates of deposit, corporate bonds, and other interest-bearing assets.
It is especially valuable for high-income earners, retirees relying on fixed income, and financial planners building tax-efficient portfolios. You can quickly test different tax rate scenarios to see how changes to your income or tax laws would impact your investment returns.
Frequently Asked Questions
What is a marginal tax rate?
Your marginal tax rate is the percentage you pay on your last dollar of taxable income. For example, if you are in the 22% federal tax bracket, you pay 22% tax on income over the threshold for that bracket. This is different from your effective tax rate, which is the average rate you pay on all your income.
Do I need to include state tax rates?
Only if the tax-exempt investment is subject to state income tax. Most municipal bonds are exempt from federal tax, but only bonds issued by your state of residence are typically exempt from state tax. If you own a bond from another state, you may owe state tax on the interest, so include your state rate in that case.
Can I use this for investments other than bonds?
Yes, this tool works for any interest-bearing investment where tax treatment differs. For example, you can compare tax-exempt money market funds to taxable savings accounts, or tax-free municipal bond ETFs to taxable bond ETFs.
Additional Guidance
- Revisit your tax equivalent calculations annually, as tax brackets adjust for inflation and your income may change over time.
- Consider consulting a tax professional before making large fixed-income investment decisions, especially if you have complex income sources or live in a high-tax state.
- Remember that tax-exempt investments may have lower yields than taxable equivalents, but the after-tax return can be higher for high-income earners.
- Use the optional taxable yield input to compare specific investments you are considering, rather than relying on generic yield quotes.