What Is YTM? Yield to Maturity Explained with Real Numbers
Every bond listing shows a YTM. Almost nobody selling bonds explains what it assumes. Since most bond decisions hinge on this one number, it’s worth ten minutes.
The three yields people confuse
Take a listed NCD with a face value of ₹1,000, a 7.6% coupon paid semi-annually, five years to maturity, quoted at a clean price of ₹985, or 98.50 per 100.
Coupon rate, 7.60%. Fixed at issue. The issuer pays ₹76 a year per bond in two ₹38 instalments, whatever price you paid.
Current yield, 7.72%. Annual coupon ÷ clean price, so 76 ÷ 985. Better, but it ignores the ₹15 you gain when a bond bought at 985 redeems at 1,000.
Yield to maturity, about 7.97%. The single discount rate at which all remaining cashflows, ten coupons plus the redemption, equal today’s dirty price. It captures the coupons, the pull to par, and the time value of both.
As a rule of thumb, a price below par means YTM above the coupon, and a price above par means YTM below it. If a platform shows a premium-priced bond with a “yield” above its coupon, that number isn’t YTM, and you can check it yourself.
The honest definition
YTM is the internal rate of return of a bond’s remaining cashflows, priced off what you pay today, meaning the dirty price of clean plus accrued interest. Formally it solves:
Dirty price = Σ CFₖ ÷ (1 + y/f)^(w+k)
where f is the coupon frequency and w is the fraction of the current coupon period remaining. There’s no closed-form solution, so calculators solve it iteratively. Ours uses Newton–Raphson to sub-basis-point precision.
One market convention trips people up: yields compound at the coupon frequency. A semi-annual 8% YTM means 4% per half-year, which is 8.16% effective annual. So when you compare a semi-annual G-sec against an annual-coupon NCD, compare effective annual yields, or compare post-tax XIRRs in the FD vs bond tool, which normalises everything.
The assumption nobody mentions
YTM assumes every coupon is reinvested at the YTM itself. If you spend your coupons, or reinvest them at lower rates, your realised return comes in below the YTM you were quoted. Two things follow.
High-coupon premium bonds depend more on reinvestment, since more of their return arrives early and has to find a home at unknown future rates.
Zero-coupon bonds are the only instruments whose YTM you’re guaranteed to realise before tax, if you hold to maturity, because there’s nothing to reinvest.
This isn’t pedantry. In a falling-rate cycle, someone who bought a 9% monthly-coupon NCD and parked the coupons in a savings account realises meaningfully less than 9%.
YTM against XIRR
XIRR, as Excel computes it, is an effective annual rate on actual dates. Bond-market YTM is a nominal rate compounded at the coupon frequency. For a semi-annual bond, XIRR ≈ (1 + YTM/2)² − 1. Platforms sometimes display whichever looks better, so it helps to know the translation. Our calculators label their conventions.
When YTM is the wrong number
If you might sell early, your return depends on the future price instead, so look at duration to size that risk.
If the bond is callable, which is typical for AT1 and perpetual paper, yield-to-call may be the binding number. A call feature favours the issuer.
After tax, two bonds with identical YTMs can differ by 40+ bps depending on how much of the return arrives as coupon rather than capital gain. The taxation guide covers why.
Try it
Take a bond you own or are considering, pull its clean price, and run it through the YTM calculator. Check three things: that the YTM matches what you were quoted, that the dirty price matches your contract note, and that the duration doesn’t exceed your sleep threshold. That covers most of bond due diligence in about three minutes.
Educational content, not investment advice. Tax rules current for FY 2026-27 to the best of our knowledge, but verify with a professional before acting. See the full disclaimer.