Bond Yield Calculator
Estimate the after-tax return on a Korean bond — coupon, compound, simple-interest, or zero-coupon — including interest income tax and trading fees, for either holding to maturity or selling early, with the full cash-flow schedule.
How to use Bond Yield Calculator
- Pick the bond type (coupon, compound, simple, or zero-coupon) and enter the face value and the price per 10,000 of face value.
- Enter the coupon rate, coupon frequency, purchase date, and maturity date. Compound and simple bonds also need the issue date so interest accrues correctly.
- Choose whether you hold to maturity or sell early; for an early sale, add the sale date and expected price.
- Add the purchase and sale fees and the interest income tax rate (15.4% in Korea) to get after-tax proceeds, the after-tax annual yield, and the deposit-equivalent rate.
- Read the cash-flow table below to see what arrives on each coupon date and how much tax is withheld.
Frequently asked questions
How much tax is withheld on bond interest in Korea?
15.4% — 14% income tax plus 1.4% local tax. If your total financial income exceeds 20 million KRW a year it is rolled into comprehensive taxation, which can raise the effective burden.
Are capital gains on bonds taxed?
For individuals in Korea they generally are not, so the calculator leaves them untaxed by default. The discount on a zero-coupon bond counts as interest and is always taxed. Turn the option on to compare a taxed case.
Why does a low-coupon bond show a high yield?
Buying below par (a price under 10,000) adds the pull to par at maturity. That gain is usually untaxed, so a cheap low-coupon bond often wins on an after-tax basis.
What is the deposit-equivalent rate?
The after-tax annual yield converted back into the pre-tax rate a bank deposit would need to match it, so you can compare it with deposit rates directly.
Why does the pre-tax annual yield differ from the coupon rate?
The coupon rate applies to face value, while the annual yield is an internal rate of return on what you actually paid and when each payment arrives, so the purchase price and coupon frequency both move it.
Is accrued interest included?
No — the calculator assumes accrued interest is already inside the purchase price. If your trade settles accrued interest separately, the real return will differ slightly.