Calculator
Bond Yield Calculator
Bond Yield Calculator
Yield to Maturity
5.01%
Yield Analysis
This bond trades at a $40 discount to par, which is why its 5.01% yield to maturity exceeds its 4.5% coupon. You collect coupons while also pocketing the price appreciation back to $1,000 at maturity.
*Assumes the bond is held to maturity, coupons are paid on schedule, and the stated price is paid. Does not model brokerage, accrued interest at settlement, or tax. Educational only, not investment advice.
Reading the Yield Behind an ASX Bond Price
When a bond trades on the ASX, investors see three numbers: the coupon it pays, the price it trades at, and — most importantly — the yield. The coupon is fixed for the life of the bond, but the price moves with interest rates and demand, so the return any buyer actually earns depends on what they pay, not just what the issuer promises. That all-in return is the yield to maturity: the annual rate that makes the price you pay today exactly equal to the present value of every future coupon and the face value at redemption. For Australian investors this matters because bond prices move inversely to rates: when the RBA lifted the cash rate, bonds with small coupons fell below par so their yields would match the new rate environment. A bond quoted at $96 with a 4.5% coupon earns more than 4.5% because the buyer also collects the discount back at maturity. Conversely a bond at $105 earns less than the coupon implies. This calculator solves for both the yield to maturity and the simpler current yield, and shows whether you are paying a premium, buying a discount, or sitting exactly at par.
Solving the Yield That Balances Price Against Promises
The calculator prices the bond as the present value of two cash-flow streams: an annuity of coupons and a single face-value payment at maturity, discounted at the unknown yield. Current yield is the simple ratio of annual coupon to price. Yield to maturity is harder — it is the discount rate y that satisfies: Price = Coupon × [1 − (1 + y)^−n] / y + Face ÷ (1 + y)^n, where n is the number of payment periods. There is no closed-form solution, so the calculator finds it by bisection, repeatedly testing rates until the model price matches your input price to within a fraction of a cent. The premium/discount tells you the direction of the answer before the math. If the price is below face value, the bond's yield must exceed its coupon — the extra return is the discount you collect at maturity. If the price is above face, yield is lower than coupon, because part of what you paid evaporates at redemption. At par, yield equals coupon exactly. Coupons paid half-yearly — the Australian government bond convention — compound slightly more frequently than annual coupons, which the calculator accounts for by splitting both coupons and the yield into per-period amounts.
Expert Insights
Yield to Maturity Is the Honest Price Tag
Never judge a bond by its coupon alone. A '6% coupon' bond at $110 might earn you under 4.5% p.a. to maturity, while a '4% coupon' bond at $92 might earn close to 5.5%. The YTM collapses price, coupon and time into the single number that lets you compare the bond against a term deposit, a savings account or another bond.
Current Yield Is a Quick Screen, Not a Decision Number
Current yield (coupon ÷ price) is useful for eyeballing income on premium bonds, but it ignores the capital gain or loss between price and face value. A premium bond where you lose $8 per $100 face at maturity looks more attractive on current yield than it really is. Use YTM for the verdict and current yield only for the income snapshot.
YTM Assumes Coupons Reinvest at the Same Rate
Yield to maturity is a promised compound return, not a guarantee. It assumes every coupon you receive is reinvested at the same yield and that you hold to maturity. If rates fall, you will reinvest lower; if you sell early, market price takes over. Long-dated bonds with high coupons carry the most reinvestment assumption — hold that caveat in mind for 10+ year horizons.
Actionable Tips
- 1
Compare the YTM Against the RBA Cash Rate
The cash rate is your risk-free benchmark. If a corporate bond's YTM sits only half a percent above the cash rate, you are not being paid much for the credit risk. Use the calculator to work out the spread after tax at your marginal rate — sometimes AGS or even a term deposit is the better deal.
- 2
Buy Discounts If You Expect Rate Cuts
Discount bonds rise in price as rates fall, and the discount you bought is banked as capital gain at maturity — plus, in Australia, the gain portion may attract the CGT discount if held twelve months or more. Premium bonds do the opposite: their price falls faster in a rate-cut cycle and you still lose the premium at redemption.
- 3
Check Accrued Interest at Settlement
ASX bond prices are quoted 'clean' — without the interest earned since the last coupon. When you buy, you pay accrued interest on top of the quoted price. Your true entry price for the YTM calculation is the clean price plus accrued, so add it back when working out exactly what you paid.
Real-World Examples
Sofia Bought the Discount, Not the Coupon
Sofia was choosing between a 7% coupon bond at $109 and a 4.8% coupon bond at $93. The 7% looked richer, but the YTM calculation showed the first earned only 5.6% to maturity while the discount bond earned 5.9%. She bought the 4.8% paper and banked the discount at maturity.
Ken Mispriced a Premium Hybrid
Ken bought a 6.5% hybrid at $106, seduced by the big coupon. This calculator showed his yield to maturity was a modest 5.4%, because the premium would evaporate at redemption and his coupons were fixed in a world of falling rates. He held to maturity and got the promised 5.4%, but never again mistook coupon for yield.
The Tran Family Held Through a Rate Cycle
The Trans bought AGS at $95 before the RBA peaked the cash rate. Their 4.6% YTM locked in at purchase, and as rates eased the bond's price recovered toward par. Holding to maturity they collected every coupon plus the full face value, exactly the 4.6% the calculator had promised at the time of purchase.
Glossary of Terms
- Yield to Maturity (YTM)
- The annual return an investor earns by buying a bond at its current price and holding it to maturity, assuming coupons are reinvested at the same rate.
- Current Yield
- The bond's annual coupon divided by its current market price — an income snapshot that ignores capital gain or loss at maturity.
- Premium / Discount Bond
- A bond trading above face value (premium) pays yield below its coupon; one trading below face (discount) pays yield above its coupon.
Frequently Asked Questions
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Ivy Sinclair-Wren
Financial Chaos Analyst
Ivy Sinclair-Wren is a Financial Chaos Analyst covering investing, AI, wealth psychology, and the emotional consequences of opening finance apps during market crashes. Based in Melbourne, she specializes in demystifying the Australian tax code and helping users navigate the intersection of spreadsheet logic and human irrationality.