How to Compare Bond Yields: YTM vs Coupon Rate vs Current Yield
Quick answer: Coupon rate is the fixed interest the issuer promises on the bond's face value. Current yield adjusts that coupon for the price you actually pay today. Yield to Maturity (YTM) is the most complete measure — it accounts for the coupon, the purchase price, any capital gain or loss at redemption, and the time value of money over the entire holding period. When comparing two bonds in the secondary market, YTM is almost always the number that matters most.
Imagine you're looking at two bonds on a platform: one is a 9% coupon NCD priced at Rs. 1,050, and another is an 8.5% coupon G-Sec priced at Rs. 960. Which actually delivers better returns? The coupon rate alone won't tell you. Even current yield falls short. To make a fair comparison, you need to understand all three yield metrics — what they measure, how they're calculated, and where each one is useful or misleading. This post walks through all three, side by side.
Key Takeaways
- Coupon rate is fixed at issuance — it tells you how much interest the issuer pays annually on the face value, but says nothing about what you'll actually earn if you buy in the secondary market.
- Current yield adjusts for market price — divide the annual coupon by the price you pay, and you get a quick read on income yield, though it ignores capital gains or losses at maturity.
- YTM is the gold standard for comparison — it incorporates coupon payments, purchase price, redemption value, and time to maturity into a single annualised figure.
- When a bond trades at a discount, YTM > current yield > coupon rate — and the reverse holds when it trades at a premium.
- YTM assumes reinvestment of coupons at the same rate — in practice, reinvestment rates vary, so realised yield may differ from the YTM quoted at purchase.
- For zero-coupon bonds, coupon rate and current yield are irrelevant — YTM is the only meaningful metric since there are no periodic cash flows.
- Callable bonds require Yield to Call (YTC) — YTM alone overstates expected return if the issuer is likely to redeem the bond early.
- Tax treatment affects your effective yield — a 9% NCD and a 7.5% tax-free bond may deliver similar post-tax returns depending on your slab; always calculate post-tax YTM for a fair comparison.
What Is the Coupon Rate?
The coupon rate is the simplest of the three metrics. When a bond is issued, the issuer sets an interest rate as a percentage of the bond's face value. That percentage is the coupon rate, and it never changes over the bond's life — regardless of what happens to market interest rates or the bond's price.
Formula:
Coupon Rate = (Annual Coupon Payment ÷ Face Value) × 100
Example: A bond with a face value of Rs. 1,000 paying Rs. 85 per year has a coupon rate of 8.5%.
Where Coupon Rate Is Useful
Coupon rate is directly useful when you're buying a bond at face value in a primary issuance — for instance, subscribing to a public NCD issue at Rs. 1,000 per bond. In that case, the coupon rate is exactly what you'll earn annually on your investment.
It also signals the bond's cash flow structure. A higher coupon rate means more income distributed periodically, which matters if you depend on regular interest payments.
Where Coupon Rate Misleads
Once a bond begins trading in the secondary market, its price diverges from face value. A bond originally issued at 8.5% may now trade at Rs. 920 or Rs. 1,080. In either case, the 8.5% coupon rate no longer reflects your actual return — and comparing two secondary-market bonds by coupon rate alone can lead you significantly astray.
What Is Current Yield?
Current yield takes one step beyond the coupon rate by accounting for the market price you actually pay. It answers a simple question: what income yield am I getting on my investment today?
Formula:
Current Yield = (Annual Coupon Payment ÷ Current Market Price) × 100
Example: The same Rs. 1,000 face-value bond with an 8.5% coupon (Rs. 85 annual interest) is now trading at Rs. 920. Current yield = (85 ÷ 920) × 100 = 9.24%.
If it traded at Rs. 1,080, current yield = (85 ÷ 1,080) × 100 = 7.87%.
Where Current Yield Is Useful
Current yield is a quick and intuitive income metric. If you're a retired investor focused on cash flow — the periodic interest credited to your account — current yield gives you a fast read on how much income Rs. 1 lakh invested today will generate annually.
It's also useful for comparing income-generating bonds at a glance, without needing to run a full YTM calculation.
Where Current Yield Misleads
Current yield ignores what happens at the end of the bond's life. If you buy a bond at Rs. 920 and it redeems at Rs. 1,000, you earn a capital gain of Rs. 80 — but current yield doesn't capture this. Conversely, if you buy at Rs. 1,080, you'll lose Rs. 80 at maturity — current yield doesn't capture that either.
For any bond trading away from face value, current yield is an incomplete picture. It's a snapshot of one dimension of return, not a total return figure.
What Is Yield to Maturity (YTM)?
YTM is the internal rate of return (IRR) of all cash flows — coupons plus final redemption — from now until the bond matures, expressed as an annualised rate. It is the single number that lets you compare any two bonds on an apples-to-apples basis, regardless of their coupon, price, or maturity.
Conceptual formula (solved iteratively):
Price = Σ [Coupon ÷ (1 + YTM)^t] + [Face Value ÷ (1 + YTM)^n]
Where t runs from 1 to n (number of periods), n is periods to maturity, and YTM is solved for.
Because this requires iteration, most investors use a financial calculator, spreadsheet (Excel's YIELD or IRR function), or the YTM calculator available on platforms like BondDekho.
Worked example: You buy a bond with face value Rs. 1,000, coupon 8.5% (paid annually), 4 years to maturity, at a price of Rs. 940.
- Annual coupon: Rs. 85
- Capital gain at maturity: Rs. 60 (1,000 − 940)
- YTM solves to approximately 10.25% — materially higher than both coupon rate (8.5%) and current yield (9.04%)
For a deeper dive into how yields move in response to price changes, see our guide on understanding bond yields and how bond prices respond to market dynamics.
The Reinvestment Assumption in YTM
YTM carries an important assumption: every coupon payment you receive is reinvested at the same YTM rate until maturity. In practice, this rarely holds perfectly — reinvestment rates fluctuate with market conditions.
If reinvestment rates fall below the YTM at purchase, your realised return will be slightly lower. If they rise, slightly higher. For long-duration bonds with many coupon payments, this reinvestment risk becomes meaningful. For zero-coupon bonds, there are no intermediate coupons to reinvest, so the YTM you calculate is exactly the return you'll earn if held to maturity.
Side-by-Side Comparison: YTM vs Coupon Rate vs Current Yield
| Feature | Coupon Rate | Current Yield | Yield to Maturity (YTM) |
|---|---|---|---|
| What it measures | Annual interest as % of face value | Annual income as % of purchase price | Total annualised return including price change |
| Formula | Coupon ÷ Face Value | Coupon ÷ Market Price | IRR of all cash flows to maturity |
| Changes with market price? | No — fixed at issuance | Yes | Yes |
| Captures capital gain/loss? | No | No | Yes |
| Useful for primary market? | Yes | Limited | Yes |
| Useful for secondary market? | Limited | Partial (income only) | Yes — primary metric |
| Works for zero-coupon bonds? | No (coupon = 0) | No | Yes |
| Bond at premium | Lowest of three | Middle | Lowest of three |
| Bond at discount | Lowest of three | Middle | Highest of three |
| Complexity | Simple | Simple | Moderate (needs calculator) |
How the Three Metrics Relate: A Numerical Example
Consider Bond A: Face value Rs. 1,000, coupon 9%, 5 years to maturity.
| Scenario | Market Price | Coupon Rate | Current Yield | YTM (approx.) |
|---|---|---|---|---|
| At par | Rs. 1,000 | 9.00% | 9.00% | 9.00% |
| At discount | Rs. 920 | 9.00% | 9.78% | 11.10% |
| At premium | Rs. 1,080 | 9.00% | 8.33% | 7.20% |
The pattern is consistent: discount bond → YTM > current yield > coupon rate; premium bond → coupon rate > current yield > YTM. Knowing this relationship helps you quickly sanity-check yield figures you see on any platform.
Beyond YTM: When You Need Other Yield Metrics
Yield to Call (YTC)
Some corporate bonds and NCDs are callable — the issuer can redeem them before the stated maturity if interest rates fall. For such bonds, the YTM calculation (which assumes cash flows run to final maturity) may overstate your return. YTC substitutes the call date and call price for the maturity date and face value.
If a bond is trading at a significant premium and is likely to be called, YTC is the more realistic metric.
Post-Tax YTM
Because coupon income is taxed at your marginal slab rate in India while long-term capital gains on listed bonds attract 12.5% LTCG tax, two bonds with identical pre-tax YTMs can deliver very different post-tax returns. A tax-free bond yielding 6.5% may outperform a taxable NCD at 8.5% for an investor in the 30% bracket. Always compute post-tax YTM before making a final comparison. Our post on bond interest taxation in India walks through the mechanics in detail.
Yield to Put (YTP)
Puttable bonds give the investor the right to sell back the bond to the issuer at a predetermined price on specified dates. YTP calculates return assuming you exercise that put at the earliest opportunity — relevant if you expect rates to rise and want the flexibility to reinvest at higher yields.
Common Mistakes Bond Yield Comparison Investors Make
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Comparing coupon rates across secondary-market bonds. A 10% coupon bond trading at Rs. 1,150 delivers a lower YTM than an 8% coupon bond trading at Rs. 850. Always use YTM for secondary-market comparisons.
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Ignoring taxation when comparing yields across instrument types. A 7.5% coupon from a AAA-rated tax-free bond and a 9.5% coupon from a taxable NCD are not directly comparable. Compute post-tax yield for both before drawing any conclusion.
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Treating YTM as guaranteed return. YTM assumes no default, no early redemption, and coupon reinvestment at the same rate. For lower-rated bonds, credit risk can render the stated YTM irrelevant if the issuer runs into trouble. Pair YTM analysis with a review of the issuer's financial health.
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Using current yield to evaluate long-duration bonds. On a 15-year bond, the gap between current yield and YTM can be enormous. Relying on current yield for such instruments gives a false sense of your total return.
Frequently Asked Questions
What is the difference between coupon rate and YTM?
Coupon rate is fixed at issuance and measures annual interest as a percentage of face value — it does not change regardless of market conditions. YTM is dynamic; it reflects the total annualised return an investor earns if they buy the bond at today's market price and hold it to maturity, accounting for both coupon cash flows and any capital gain or loss. For a bond purchased exactly at face value, the two numbers coincide. For any bond trading above or below face value in the secondary market, they will differ, sometimes substantially.
Which yield metric should I use when comparing two bonds?
YTM is the most comprehensive and appropriate metric for comparing any two bonds in the secondary market. It normalises for differences in coupon rate, price, and maturity into a single annualised figure. If taxation differs between the two instruments — for instance, one is tax-free and the other is fully taxable — compute post-tax YTM for a genuinely fair comparison.
Why is YTM higher than the coupon rate when a bond trades at a discount?
When you buy a bond below face value, you receive two sources of return: the periodic coupon payments and a capital gain when the bond redeems at face value. YTM captures both. Current yield captures only the coupon relative to purchase price, and coupon rate ignores the discounted purchase price entirely. The capital gain component is what pushes YTM above the other two metrics for discount bonds.
Does YTM account for reinvestment of coupons?
Yes — and this is a key limitation to understand. The standard YTM calculation assumes each coupon received is immediately reinvested at the same YTM rate until maturity. If market rates fall after your purchase, you'll reinvest coupons at lower rates, and your realised return will fall slightly short of the YTM quoted at purchase. This is called reinvestment risk, and it's more pronounced for high-coupon, long-duration bonds. Zero-coupon bonds eliminate reinvestment risk entirely.
How does RBI rate changes affect the YTM of bonds I already hold?
When RBI raises the repo rate, newly issued bonds carry higher coupons, making existing bonds less attractive. Their market prices fall until their YTMs rise to match the new market rate. If you hold to maturity, your cash flows remain unchanged — you still receive the original coupons and face value. But if you sell before maturity, you'll receive a lower price. Conversely, when RBI cuts rates, existing bond prices rise and YTMs compress. Our post on RBI rate changes and your bond portfolio explores this dynamic in detail.
Can I rely on the YTM shown on a bond platform?
The YTM figure displayed on most platforms is calculated using standard bond pricing conventions and is generally accurate as a pre-tax, pre-fee indication. However, always verify: (a) whether the yield is pre-tax or post-tax, (b) whether transaction costs and platform fees are included, (c) whether the bond has any embedded options (call/put) that might make YTC or YTP more relevant, and (d) the settlement date used, since accrued interest affects the dirty price you actually pay. If you're evaluating a bond's fact sheet, our guide on how to read a bond fact sheet covers all the fields you need to check.
Bottom Line
Coupon rate tells you what an issuer promises. Current yield tells you today's income on your investment. YTM tells you the whole story — total annualised return from purchase price through to final redemption. For virtually any secondary-market bond comparison, YTM is the metric to anchor on, with post-tax YTM providing the most honest like-for-like view once taxation enters the picture. Understanding how all three metrics relate — and why they diverge when bonds trade away from face value — is one of the most transferable skills in fixed income investing. Once you can read yield numbers confidently, evaluating bonds across platforms, maturities, and credit ratings becomes significantly more straightforward.
Disclaimer: This post is for educational purposes only. BondDekho is not a SEBI-registered investment adviser. Yields and risks mentioned are illustrative; consult a SEBI-registered adviser before making any investment decision.