🌍 Eurobond Yield Calculator

What is a Eurobond?

A Eurobond is a debt security distributed in international markets, often outside the issuer’s domestic market. The name does not mean that the bond must be issued in euros. Governments and companies can raise funds by issuing international bonds in various currencies. In Turkey, the term commonly refers to the Republic of Türkiye’s foreign-currency external debt securities, including those traded on Borsa İstanbul’s International Bonds Market.

The issuer owes payments according to the bond’s terms. Face value (principal or nominal amount) is the amount scheduled for redemption at maturity; a coupon is a periodic interest payment. A fixed-rate coupon bond may pay interest several times before maturity. A zero-coupon bond has no scheduled interim coupon in the simple scenario modeled here; the difference between purchase cost and redemption amount drives its return.

What can the calculator do? Two different modes

The default “Yield from purchase price” mode takes your price as an input. It assumes a regular coupon schedule, lists every modeled post-purchase cash payment through maturity, and finds the annual discount rate that balances the dated inflows with the initial purchase outflow. It also reports purchase cost, total receipts, holding-period profit or loss, and a signed cash-flow table.

The separate “Theoretical price from yield” mode works in the other direction: you enter an assumed annual yield, coupon terms and remaining coupon periods to calculate a theoretical price. Do not mistake a price calculated from an assumed yield for a yield inferred from an actual purchase price.

How to calculate yield from your purchase price

1. Stay in “Yield from purchase price” and select USD or EUR for the output unit. Currency selection is a label, not conversion.
2. Choose zero coupon or coupons every month, three months, six months or year. If coupons are enabled, enter the annual coupon percentage.
3. Select whether the entered price is clean or dirty. A quoted price of 98 means 98 for every 100 units of face value; it does not mean you pay 98 for the entire holding.
4. Enter face amount and valid purchase and maturity dates using day, month and year. Maturity must be later than purchase.
5. Choose “Calculate”. Read the effective annual yield first, then the dirty purchase cost, total receipts, profit or loss and full dated payment table. Editing any input clears the old result until you calculate again.

For example, a clean price of 98 against 10,000 USD face value corresponds to 9,800 USD before any modeled accrued coupon interest. A trade between coupon dates may have a higher dirty settlement consideration.

Clean price, dirty price and accrued interest

Clean price excludes coupon interest accrued since the previous coupon date; dirty price includes it. In the calculator, dirty price = clean price + modeled accrued interest, expressed per 100 of face value. Modeled purchase cost = face amount × dirty price / 100. Borsa İstanbul describes both the price-per-100 quotation basis and the distinction between these price types.

Enter just one price type. Entering clean price makes the calculator add its calculated accrual; entering dirty price lets it derive clean price by subtraction. Two entries representing the same economic price give the same modeled result, apart from displayed rounding. If dirty price is less than accrued interest, the resulting clean price would be negative, so the calculator refuses the inputs.

For a regular coupon interval, the calculator allocates the period coupon according to the actual days elapsed divided by the actual days in that interval. This is an explicitly chosen Actual/Actual-like scenario rule. Different securities can follow different contractual day-count conventions, including 30E/360, so a broker’s accrued interest may differ.

Coupon rate, annual effective yield and total profit are not the same

A coupon percentage is applied to face value to calculate scheduled coupon amounts. Holding-period profit percentage measures total modeled receipts minus initial dirty cost, divided by that cost, over the entire purchase-to-maturity interval. Effective annual yield also takes into account exactly when the coupons and principal are expected to arrive.

The model represents the purchase as a negative cash flow on the purchase date, followed by positive coupons and principal repayment. It solves for the annual rate r that makes the sum of dated cash flows, each discounted using days elapsed / 365, equal to zero. This is the dated cash-flow convention used by Microsoft Excel’s XIRR function; it does not adjust for the risk that future payments might not occur.

For a zero-coupon scenario, annual effective yield = (face value received at maturity / dirty purchase cost) ^ (365 / days held) − 1. Dividing the total percentage profit by the number of years does not generally reproduce that compounded annual rate.

Example: Zero coupon, a two-year holding period

Consider a hypothetical zero-coupon security with face value of USD 10,000, a clean price of 95, purchased on 1 January 2026 and maturing on 1 January 2028. You pay USD 9,500, receive USD 10,000 at maturity and earn USD 500 over the period, or 5.26% of the initial cost.

The interval is 730 days, so the effective annual rate is (10,000 / 9,500) ^ (365 / 730) − 1, approximately 2.60%. The signed cash-flow table has only two rows: −9,500 on 1 January 2026 and +10,000 on 1 January 2028. These are assumed contractual payments, not evidence of an actual offer.

Example: Buying a coupon bond between payment dates

Suppose face value is USD 10,000, annual coupon 8% paid every six months, clean price 98, purchase date 1 April 2026 and maturity 1 January 2028. The modeled surrounding coupon dates are 1 January and 1 July 2026. Each full coupon is USD 400. Accrued interest is approximately 1.989 per 100 of face value; dirty price is approximately 99.989 and modeled purchase cost is USD 9,998.90.

Future coupons of USD 400 are modeled on 1 July 2026, 1 January 2027 and 1 July 2027. On 1 January 2028 the model combines the final USD 400 coupon with USD 10,000 principal. Total modeled receipts equal USD 11,600 and profit equals USD 1,601.10 (16.01% over the entire holding period). The dated effective annual yield is approximately 9.45%. Entering 99.989 as dirty price produces equivalent displayed results within rounding.

This worked example explains the method. It does not validate an actual security’s coupon calendar, market price or ability to pay.

Coupon dates, days remaining and historical scenarios

The calculator constructs regular coupon dates backward from the maturity date, in 1-, 3-, 6- or 12-month steps. When the maturity falls on the 29th, 30th or 31st, a shorter coupon month is clamped to its final calendar day. Thus an assumed semiannual bond maturing on 31 August 2027 has a modeled coupon date of 28 February 2027. This is a deterministic calculator rule, not a statement about every bond’s legal schedule.

Total holding period runs from the purchase date to maturity. “Days remaining” and “next coupon” are different values measured as of today. If the purchase date is in the future, the result is marked as a future scenario; when maturity is past, historical cash flows remain visible but no future coupon or days-remaining claim is made.

Coupon payment dates are not shifted for local holidays, weekends or contractual business-day conventions. A real bond may pay on an adjusted date or follow a different stub-period calendar.

Which investment risks are outside this calculation?

Credit or default risk is the possibility that the issuer does not make promised interest or principal payments. Market interest rates affect a bond’s resale price before maturity; liquidity may determine whether a buyer is available at all. The calculator’s hold-to-maturity result will generally differ from what you realise if you sell early.

USD and EUR in this tool are output labels only. No TRY conversion, exchange-rate scenario, inflation adjustment or after-tax return is calculated. Review the relevant prospectus, security-specific schedule, credit information and brokerage terms before relying on a transaction amount.

• Do not confuse coupon rate with effective annual yield.
• Do not type a total cash amount into a price-per-100 input.
• Do not treat the presence of monthly or quarterly controls as proof that a real Eurobond pays at that frequency.
• Do not use the modeled coupon schedule as a substitute for the issue’s published payment dates.
• Check that maturity is after purchase and all dates are valid calendar dates.

For related questions, the site also has a bond calculator (Tahvil), a bill calculator (Bono), an internal rate of return calculator (İç Verim Oranı, IRR) and an interest-discounting calculator (İç ve Dış İskonto).