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Tax Equivalent Yield Calculator
Compare Tax-Free vs. Taxable Returns
Should you pick a municipal bond or a corporate bond? Stop guessing. Enter your tax-free yield and marginal tax rate to instantly see the taxable return that would match — and discover which investment keeps more money in your pocket.
Tax Equivalent Yield Calculator
TEY = Tax-Free Yield ÷ (1 − Marginal Tax Rate)
| Metric | Tax-Free Bond | Taxable Equivalent |
|---|---|---|
| Run calculation to see results | ||
Compare up to 3 different tax-free bonds to find the best equivalent yield for your tax bracket.
| Bond | Tax-Free Yield | TEY (Taxable Equiv.) | Advantage |
|---|
What Is Tax Equivalent Yield and Why Does It Matter?
When comparing investments, most people look at the stated interest rate — also called the nominal yield. But that number alone is incomplete. Taxes quietly erode the income you actually receive, and the size of that erosion depends entirely on your tax bracket. Tax Equivalent Yield (TEY) solves this problem by converting a tax-free return into the taxable return that would produce identical after-tax income.
Think of it this way: a municipal bond offering 3.5% may sound less exciting than a corporate bond paying 5.2%. But if you’re in the 32% federal tax bracket, your after-tax corporate yield drops to about 3.54% — barely better than the muni. Once you add state taxes, the corporate bond may actually deliver less real income. Without the TEY calculation, that comparison is invisible.
This tool matters for anyone investing in fixed-income assets — from retirees building income portfolios to high-income professionals evaluating their options. The higher your tax bracket, the more dramatic the difference. For a 37% taxpayer, a 4% tax-free yield is equivalent to a taxable investment paying over 6.3%. That gap is too significant to ignore.
Municipal Bonds
The most common tax-free investment. Interest is usually exempt from federal taxes and often state taxes if issued in your home state, making TEY especially powerful here.
Who Benefits Most?
Investors in the 24% bracket and above typically gain the most from tax-equivalent yield analysis. The advantage compounds over multi-year holding periods.
Simple Formula
TEY = Tax-Free Yield ÷ (1 − Tax Rate). While the math is simple, the decision it informs can mean thousands of dollars in annual difference.
A Fair Comparison
TEY puts tax-free and taxable bonds on equal footing so you compare real returns — not marketing numbers — and choose the investment that genuinely benefits you.
How to Use This Tax Equivalent Yield Calculator
- 1
Enter Your Tax-Free Yield
Find the stated yield on your municipal bond or other tax-exempt security. Enter it as a percentage (e.g., 3.5 for 3.5%). This is typically shown on the bond’s offering sheet or your brokerage dashboard.
- 2
Select or Enter Your Marginal Tax Rate
Use the dropdown for standard 2024–2025 federal brackets, or enter a custom rate for combined federal + state analysis. Your marginal rate — the rate on the last dollar of income — is what matters here, not your average rate.
- 3
Add State Tax (Optional but Recommended)
If the tax-free bond is NOT exempt from your state taxes, enter your state rate. If it IS state-exempt (bonds issued in your state of residence), leave this at 0. The difference can swing the result by 2–5 percentage points.
- 4
Compare Your Result to the Market
Once you see the TEY, compare it to yields currently available on taxable corporate bonds or CDs of similar credit quality and duration. If the TEY exceeds what you can find in taxable alternatives, the tax-free bond wins.
- 5
Use Advanced Mode for Deeper Analysis
Switch to Advanced Mode to include local taxes, enter an investment amount, and see a multi-year projection of tax savings — ideal for retirement planners and investors making large allocation decisions.
Understanding U.S. Federal Tax Brackets and TEY Impact
The relationship between your tax bracket and tax equivalent yield is not linear — it accelerates at higher income levels. Understanding where you fall on the bracket ladder is essential for accurate TEY calculations.
| Federal Bracket | Taxable Income (Single, 2024) | Tax-Free 3.5% Equivalent TEY | Tax-Free 4.0% Equivalent TEY |
|---|---|---|---|
| 10% | Up to $11,600 | 3.89% | 4.44% |
| 12% | $11,601 – $47,150 | 3.98% | 4.55% |
| 22% | $47,151 – $100,525 | 4.49% | 5.13% |
| 24% | $100,526 – $191,950 | 4.61% | 5.26% |
| 32% | $191,951 – $243,725 | 5.15% | 5.88% |
| 35% | $243,726 – $609,350 | 5.38% | 6.15% |
| 37% | Over $609,350 | 5.56% | 6.35% |
This table illustrates a crucial insight: as tax rates rise, the advantage of tax-free bonds grows disproportionately. A 3.5% tax-free yield is worth 3.89% to a 10% bracket investor but 5.56% to a 37% bracket investor. The tax-free bond is the same; the tax benefit multiplied it by 59% more for the high-income earner.
Tax Equivalent Yield vs. After-Tax Yield: Know the Difference
These two terms are often confused, but they measure different things and serve different purposes in investment analysis.
Tax Equivalent Yield (TEY) answers the question: “What taxable yield would I need to match this tax-free return?” It converts the tax-free rate upward. It’s used for comparison — specifically when you want to evaluate whether a taxable bond is worth choosing over a tax-free one.
After-Tax Yield answers a different question: “What return do I actually keep after paying taxes?” It converts a taxable rate downward. Formula: After-Tax Yield = Taxable Yield × (1 − Tax Rate). If a corporate bond pays 5.5% and your tax rate is 24%, your after-tax yield is 5.5% × 0.76 = 4.18%.
The two are mathematical inverses. Comparing TEY to the stated taxable yield, or after-tax yield to the stated tax-free yield, both lead to the same decision — they’re just different angles on the same truth. This calculator focuses on TEY because it’s more intuitive: investors naturally compare stated yields, so raising the tax-free yield to a taxable equivalent makes the comparison easy.
When Should You Choose Tax-Free Bonds Over Taxable Ones?
The TEY calculation gives you a crossover point. If you can find taxable bonds paying more than the TEY, the taxable bond wins — you’re earning more after tax. If taxable yields fall below the TEY, the tax-free bond is the better deal. But several other factors influence the complete picture:
Credit Quality and Risk
Municipal bonds vary enormously in credit quality. General obligation (GO) bonds backed by taxing authority are typically safer than revenue bonds backed only by a project’s cash flow. Never compare yields without considering whether you’re accepting more credit risk for the higher yield. A corporate bond paying 5.5% may genuinely justify its higher rate if it carries substantially more default risk than the 3.5% muni.
Bond Duration and Interest Rate Risk
Longer-duration bonds are more sensitive to interest rate changes. If rates rise, long-term bond prices fall more sharply. When calculating TEY for longer-maturity bonds, factor in that you’re locking in that yield for a longer period — which carries more interest rate uncertainty.
Alternative Minimum Tax (AMT)
Some municipal bonds — specifically private activity bonds (PABs) — are subject to the Alternative Minimum Tax. This is a critical caveat: if you’re subject to AMT, some “tax-free” bonds aren’t fully exempt. Always verify whether a muni is an AMT bond before assuming full exemption. The IRS provides guidance on AMT-exempt securities.
Account Type Matters
Tax-equivalent yield analysis applies specifically to taxable brokerage accounts. In a tax-deferred account like a Traditional IRA or 401(k), or a tax-exempt account like a Roth IRA, putting tax-free bonds is often suboptimal — you’re wasting the tax benefit by placing it where taxes are already deferred or eliminated. Municipal bonds typically belong in taxable accounts; taxable bonds often belong in tax-advantaged accounts. This asset location strategy can be more powerful than TEY analysis alone.
Real-World Example: Should You Buy the Muni or the Corporate?
Let’s walk through a real decision. You have $250,000 to invest and are choosing between two bonds of similar credit quality and 10-year maturity:
Option A: A California state general obligation municipal bond yielding 3.8%. Interest is exempt from federal and California state taxes.
Option B: A corporate bond from a highly rated company yielding 5.6%.
You’re a California resident with combined federal (35%) and state (9.3%) marginal rates, totaling 44.3%.
TEY of the municipal bond: 3.8% ÷ (1 − 0.443) = 3.8% ÷ 0.557 = 6.82%
The corporate bond pays 5.6%. The equivalent TEY of your muni is 6.82%. The muni wins — by a significant margin. Over 10 years on $250,000, that difference compounds substantially. The muni generates approximately $9,500 per year tax-free. The corporate bond generates $14,000 per year, but after 44.3% tax, you keep only $7,798. The muni puts $1,702 more in your pocket every single year — $17,020 over the decade, before reinvestment.
Without the TEY calculator, you might have chosen the corporate bond for its higher stated yield. That would have been a costly mistake.
Common Mistakes When Using Tax Equivalent Yield
Using Average Tax Rate Instead of Marginal Rate
Your average (effective) tax rate is what you pay overall; your marginal rate is what applies to the next dollar of income. Since investment interest income sits on top of your regular income, it’s taxed at the marginal rate. Using your lower average rate will overstate the appeal of taxable bonds.
Ignoring State Tax Exemptions
Many investors correctly enter their federal rate but forget that in-state municipal bonds are often exempt from state income tax as well. Omitting state taxes dramatically understates the TEY for residents of high-tax states.
Comparing Bonds of Different Risk Profiles
TEY is a yield adjustment tool, not a risk-assessment tool. Comparing a AAA-rated muni to a junk-rated corporate bond on TEY alone ignores a fundamental difference in default probability. Always compare bonds at similar credit quality levels.
Applying TEY to Tax-Advantaged Accounts
Inside a Roth IRA or Traditional IRA, the tax calculation is completely different. TEY analysis applies only to taxable brokerage accounts where investment income is taxed annually.
