Calculator Inputs
Example Data Table
| Scenario | Face Value | Price | Coupon | Combined Interest Tax | After-Tax Current Yield | Notes |
|---|---|---|---|---|---|---|
| Discount Corporate Bond | $1,000 | $960 | 5.00% | 24.00% | 3.96% | Lower price lifts yield despite taxes. |
| Premium Agency Bond | $1,000 | $1,020 | 4.00% | 12.00% | 3.45% | Premium price softens net return. |
| Tax-Exempt Municipal Bond | $1,000 | $980 | 3.00% | 0.00% | 3.06% | Useful for taxable-equivalent comparisons. |
| High-Bracket Income Bond | $1,000 | $1,050 | 6.00% | 37.00% | 3.60% | Taxes reduce headline coupon sharply. |
Formula Used
1. Combined interest tax rate
1 - (1 - Federal) × (1 - State) × (1 - Local)
2. Annual coupon income
Face Value × Coupon Rate
3. After-tax annual coupon
Annual Coupon × (1 - Combined Interest Tax Rate)
4. After-tax current yield
After-Tax Annual Coupon ÷ Purchase Price
5. After-tax redemption value
Face Value - ((Face Value - Purchase Price) × Capital Gains Tax Rate)
6. After-tax yield to maturity
The calculator builds after-tax cash flows for every payment period, then solves the internal rate of return across those net cash flows.
7. Taxable-equivalent yield
After-Tax Yield ÷ (1 - Combined Interest Tax Rate)
Taxable-equivalent yield is especially useful for comparing tax-exempt bonds against fully taxable alternatives.
How to Use This Calculator
- Enter the bond name, face value, purchase price, coupon rate, and years to maturity.
- Select the coupon payment frequency that matches the bond’s schedule.
- Enter your federal, state, local, and capital gains tax rates.
- Check any exemption boxes if the bond’s interest is tax-exempt.
- Press Calculate After-Tax Yield to see results above the form.
- Review current yield, after-tax YTM, redemption value, and total tax effect.
- Use the CSV and PDF buttons to save the summary.
- Read the graph to compare pre-tax and after-tax cash flows by period.
FAQs
1. What does after-tax bond yield measure?
It measures the return you keep after estimated taxes reduce coupon income and any taxable gain at maturity. It focuses on net investable return rather than headline coupon figures.
2. Why does purchase price affect the result so much?
Yield depends on both income and cost. Buying below face value can raise return, while paying a premium can reduce it. Price also changes the capital gain or loss realized at maturity.
3. When is taxable-equivalent yield most helpful?
It is most helpful when comparing municipal or partially tax-exempt bonds with fully taxable corporate or treasury issues. It shows the taxable yield needed to match the net tax-advantaged return.
4. Are coupon taxes and capital gains taxes treated differently?
Yes. Coupon income is typically taxed as interest income, while the gain or loss between purchase price and face value is usually handled through capital gains tax assumptions.
5. Why can after-tax YTM differ from after-tax current yield?
Current yield only uses annual coupon income relative to price. YTM includes all scheduled payments, time value, and the maturity value, so it captures a fuller return picture.
6. Does payment frequency change the calculation?
Yes. Semiannual, quarterly, or monthly payments change the timing of cash flows. That timing affects internal rate of return calculations and can slightly change annualized yield values.
7. How should I enter a tax-exempt municipal bond?
Enter the bond terms normally, then tick the interest exemption boxes that apply. This removes those taxes from coupon income and makes the taxable-equivalent comparison more meaningful.
8. Is this calculator a tax filing tool?
No. It is an educational estimating tool for investment analysis. Actual tax treatment can vary by jurisdiction, account type, holding period, and current law.