Calculator
Bond Yield to Maturity Calculator
Bond Yield to Maturity Calculator
Yield to Maturity
5.43%
Yield Analysis
Bought at $9,750, this bond sits $250 below par, so its 5.43% yield to maturity runs above the 5% coupon. YTM folds together the coupons you collect and the capital gain you bank when the issuer redeems it at $10,000 — the honest all-in figure to compare against term deposits and other bonds.
*Assumes the bond is held to maturity, coupons are paid on schedule, and the stated price is paid. The realised yield also depends on the coupon reinvestment rate you assume. Does not model brokerage, accrued interest, or tax. Educational only, not investment advice.
The Single Most Important Number in Bond Investing
Yield to maturity is the bond investor's bottom line: the annualised return you will earn if you buy at today's price, collect every coupon on schedule, and hold until the issuer redeems the bond at face value. It is the one figure that lets you compare a Commonwealth bond against a hybrid, a corporate paper against a term deposit, because it folds together the three forces that decide a bond's return — the coupon, the price you pay relative to face value, and the time you hold it. In the Australian market this number has mattered more since the RBA's rate cycle turned. Bonds bought before 2022 trade well below par, so their yield to maturity now includes the built-in gain of the price recovering to face at maturity. Newer bonds trade closer to par with higher coupons. Either way, the coupon alone is misleading — a generous coupon on an expensive bond can deliver less than a modest coupon on a cheap one. This calculator solves the yield to maturity by iteration, shows how it compares with the simple current yield, and adds the dimension professionals check next: what happens if you must reinvest each coupon at a rate different from the yield itself.
Iterating to the Rate That Balances Price and Promise
The price of a bond equals the present value of its remaining coupons plus the present value of its face value at maturity, each discounted at the unknown yield y: Price = Coupon × [1 − (1 + y)^−n] / y + Face ÷ (1 + y)^n, where n is the number of remaining payment periods. No algebraic formula solves this equation for y, so the calculator uses bisection: it tests candidate rates, compares the modelled price with your input price, and narrows the search interval until the two agree to within a fraction of a cent. Coupons paid half-yearly — the Australian convention for AGS and most ASX-listed bonds — are handled by halving the coupon and doubling the period count. Alongside the YTM, the calculator reports the current yield — annual coupon divided by price — the simpler income snapshot. It then answers the question YTM leaves open: the realised compound yield. YTM assumes coupons reinvest at the yield itself; if you reinvest at a different rate, the actual outcome differs. The tool compounds each coupon at your chosen reinvestment rate through to maturity and converts the final maturity value back into a per-annum figure, showing exactly how sensitive your return is to that reinvestment assumption.
Expert Insights
Reinvestment Risk Is Real — Model It
Yield to maturity is a promise, not a guarantee: it assumes coupons are reinvested at the YTM itself. For long-dated, high-coupon Australian bonds, that assumption may be optimistic if rates fall. Always check the realised yield under a lower reinvestment rate; the gap between the two figures is the reinvestment risk you are quietly accepting.
The Discount Is the Quiet Gift
Bonds bought below par collect the discount as a near-certain capital gain at maturity, and that gain is taxed more favourably than coupon income if the bond is held over twelve months. A discount AGS held to maturity converts part of your return from ordinary income (marginal rate) into a capital gain (potentially the 50% discount) — a genuine structural edge for Australian individual investors.
Use YTM to Rank Everything on Your Watchlist
When deciding between a bond ETF, an individual bond, a hybrid, and a term deposit, put every option's yield on the same tax-adjusted footing: multiply YTM by (1 − marginal rate) for taxable holdings, or by (1 − 0.15) inside accumulation super. The ranking can flip completely after tax, especially at the 37%+ marginal rates.
Actionable Tips
- 1
Set Your Reinvestment Rate To Something Honest
If you will sweep coupons into a cash account or short-dated notes, use the current short rate as your reinvestment assumption, not the bond's YTM. The realised yield the calculator produces then becomes a genuinely conservative planning number rather than the optimistic built-in assumption.
- 2
Buy Discounts When You Can't Reinvest Higher
If rates look like falling, prefer discount bonds: more of your return is locked into the price-recovery gain, and less depends on reinvesting coupons at today's higher rates. The calculator shows the trade — a discount bond's realised yield barely moves as the reinvestment rate drops, while a premium bond's does.
- 3
Time Maturity To Your Goal
YTM only guarantees your return at maturity. If you may need to sell earlier, the remaining years slider shows how much price volatility you inherit. For a fixed future liability — school fees, a renovation, a retirement date — set years to maturity to match the date, and the calculated yield becomes your assured return.
Real-World Examples
Alan Chose the Discount AGS Over the Flashy Hybrid
Alan compared a 7.5% hybrid at $107 against an AGS with a 4.8% coupon at $92. The hybrid looked richer, but the YTM calculator showed the AGS earned 5.9% to maturity with the discount to come, versus 6.1% on the hybrid — for far less risk and better tax treatment. He took the government paper and the near-identical yield.
Fiona Found the Reinvestment Trap
Fiona held a 10-year bond with a 6% coupon and assumed she was earning 6.1% YTM. The realised-yield panel showed that if coupons reinvested at only 4%, her true return fell to 5.4%. She moved her bond allocation into short maturities maturing before she expected rates to drop, removing most of the gap.
The Patels Matched Maturity to Their Goal
The Patels needed $250,000 in five years for their daughter's deposit. They bought a bond maturing in exactly five years with a 5.6% YTM at their purchase price. The calculator confirmed that, coupons reinvested in their offset, the maturity value would land within $8,000 of the target — certainty a balanced fund could not offer.
Glossary of Terms
- Yield to Maturity (YTM)
- The annualised return earned by buying a bond at its market price and holding to maturity, assuming all coupons are reinvested at the same rate.
- Reinvestment Rate
- The actual rate at which received coupons are re-invested; the realised compound yield only equals YTM if this rate matches the YTM itself.
- Bisection Method
- The iterative numerical technique the calculator uses to home in on the yield that makes the modelled bond price equal your input price.
Frequently Asked Questions
Everything you need to know about this topic.
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.