What Is Yield to Maturity? Bond Returns Explained

Yield to maturity (YTM) is the total annual return you'll earn on a bond if you buy it at the current market price and hold it until it matures — accounting for the coupon payments, the difference between the purchase price and face value, and the time remaining until maturity. It's the single most important metric for comparing bonds and the closest thing to a bond's "expected return."

Why YTM Matters More Than Coupon Rate

A bond's coupon rate tells you the annual interest payment as a percentage of face value — but if you buy the bond at a price different from face value, the coupon rate doesn't reflect your actual return. A bond with a 5% coupon trading at $1,100 (above its $1,000 face value) yields less than 5% because you paid a premium that will be lost when the bond matures at $1,000. A bond with a 3% coupon trading at $900 (below face value) yields more than 3% because the discount provides an additional gain at maturity.

YTM captures all of this: the coupon income, the capital gain or loss from the price-to-face-value difference, and the time value of money. It's the internal rate of return of the bond — the discount rate at which the present value of all future cash flows (coupons plus face value at maturity) equals the current market price.

How YTM Is Calculated

The YTM calculation solves for the discount rate in the present value equation: Current Price = (Coupon / (1+YTM)) + (Coupon / (1+YTM)²) + ... + ((Coupon + Face Value) / (1+YTM)ⁿ). This can't be solved algebraically — it requires iteration or a financial calculator. Most bond data providers display YTM alongside price and coupon, so you rarely need to calculate it manually.

A simplified approximation: YTM ≈ (Annual Coupon + (Face Value − Price) / Years to Maturity) / ((Face Value + Price) / 2). For a $1,000 bond with a 4% coupon bought at $950 with 5 years to maturity: YTM ≈ ($40 + ($50/5)) / (($1,000 + $950) / 2) = $50 / $975 ≈ 5.1%. The actual YTM accounting for compounding would be slightly different.

YTM and Bond Decisions

YTM allows apples-to-apples comparison between bonds with different coupons, prices, and maturities. A 10-year bond with a 6% coupon at $1,050 and a 10-year bond with a 4% coupon at $920 may have similar YTMs despite very different coupon rates and prices. The YTM tells you which one delivers the better total return.

YTM also serves as the opportunity cost benchmark for stock investors. When the 10-year Treasury YTM is 5%, a stock must offer expected returns meaningfully above 5% to justify the additional equity risk. Rising YTMs make bonds more competitive with stocks; falling YTMs make stocks more attractive relative to bonds.

Limitations

YTM assumes you hold to maturity (selling early produces different returns), that coupon payments are reinvested at the YTM rate (which may not be achievable), and that the issuer doesn't default (relevant for corporate and high-yield bonds). For Treasury bonds, the no-default assumption is safe; for junk bonds, the actual return may be lower than YTM if the issuer defaults.