Yield to Maturity Calculator: What Your Bond Is Actually Paying You

When you buy a bond, three different yield numbers exist: the coupon rate, the current yield, and the yield to maturity (YTM). Most investors focus on the coupon rate because it's printed on the bond. That's the wrong number to focus on.

Yield to maturity is the one that tells you what you're actually earning if you hold the bond to its end date, accounting for what you paid for it.

Three Yields, Three Different Answers

Take a bond with a $1,000 face value, paying a 4% annual coupon, currently trading at $950, with 5 years left to maturity.

Coupon rate: 4%. This is the interest rate based on face value. You receive $40/year in interest regardless of what you paid.

Current yield: $40 / $950 = 4.21%. This adjusts the return for what you actually paid, but ignores the $50 gain you'll receive when the bond matures at $1,000.

Yield to maturity: ~5.14%. This is the total annualized return accounting for coupon payments, the discount from face value you paid, and time to maturity.

YTM of 5.14% is the number that tells you: "If you buy this bond today and hold it to maturity, you'll earn 5.14% per year."

How YTM Is Calculated

YTM doesn't have a simple formula — it's solved iteratively. The concept is straightforward: what discount rate makes the present value of all future cash flows equal to the current price?

For the example above:

• You pay $950 today
• You receive $40/year for 5 years = $200 in coupons
• You receive $1,000 at maturity
• Total cash received: $1,200
• Total gain over purchase price: $250
• Annualized to get the effective rate = approximately 5.14%

The exact calculation requires trial-and-error or a financial calculator. The rough shortcut:

Approximate YTM = (Annual coupon + annual gain to par) / average of price and par

= ($40 + $10) / (($950 + $1,000) / 2) = $50 / $975 = 5.13%

Close enough for comparison purposes.

Why Bond Prices and Yields Move Inversely

This is the fundamental principle many investors get backwards: when bond prices go up, yields go down, and vice versa.

Here's why: if you own a bond paying $40/year and interest rates rise to 6%, new bonds pay $60/year. Your old bond becomes less attractive, so its price drops until buyers receive the equivalent of 6% on what they pay. The coupon stays at $40, but the price falls to make the math work.

Rising interest rates = falling bond prices Falling interest rates = rising bond prices

This matters when buying existing bonds in the secondary market, which is how most individual bond purchases happen.

Using YTM to Compare Bonds

YTM is the only apples-to-apples comparison metric across bonds of different maturities, coupon rates, and prices.

| Bond | Face Value | Coupon | Price | Years to Maturity | YTM | |------|------------|--------|-------|-------------------|-----| | A | $1,000 | 5% | $1,050 | 10 | 4.39% | | B | $1,000 | 3% | $920 | 7 | 4.51% | | C | $1,000 | 4% | $950 | 5 | 5.14% |

Looking only at coupon rates, Bond A appears best at 5%. But comparing YTM tells you Bond C delivers the highest total return if held to maturity, because you're buying it at a discount.

YTM Limitations

Assumes reinvestment at the same rate: YTM implicitly assumes every coupon payment gets reinvested at the YTM rate. In falling rate environments, this overstates actual returns.

Assumes hold to maturity: If you sell before maturity, your actual return will differ based on the price you sell at.

Doesn't account for credit risk: Two bonds with identical YTM but different credit ratings aren't equivalent. Higher yield on a lower-rated bond compensates for default probability, not just return.

Callable bonds: If the bond can be called (redeemed early by the issuer), use yield to call (YTC) rather than YTM. Companies call bonds when rates drop, removing your high-yielding investment at the worst time.

YTM vs. TIPS and I-Bonds

For inflation-protected bonds:

• TIPS (Treasury Inflation-Protected Securities): YTM is quoted as a real yield — the return above inflation. A TIPS with YTM of 1.8% returns 1.8% plus CPI.
• I-Bonds: Fixed rate + inflation component. Currently paying 4.28% composite rate (as of late 2025). No YTM in the traditional sense since the rate adjusts semi-annually.

Real yields on TIPS above 2% are historically attractive, meaning you earn meaningful positive returns after inflation.

Run the Numbers

Use the CalcMoney Investment Return Calculator to model bond portfolios against equity allocations and compare expected returns across different asset classes over your investment horizon.