Bond Yield: What It Is, Why It Matters, and How It's Calculated

Definition

Bond yield is the annual interest that the holder of a bond will receive over its term to maturity.

Key Takeaways

  • Bond yield is the return an investor realizes on an investment in a bond.  
  • A bond can be purchased for more than its face value, at a premium, or less than its face value, at a discount.
  • The current yield is the bond's coupon rate divided by its market price.
  • Price and yield are inversely related, and as the price of a bond goes up, its yield goes down.

What Is a Bond Yield?

A bond yield is the return on the capital invested in a bond. The yield matches the bond's coupon rate when the bond is issued, though the yield often changes while the bond is outstanding. Bond yields can be derived in different ways, factoring in the coupon yield and current yield.

Bond Yield
Bond yield is calculated by dividing the bond's annual coupon payment (the interest the bond pays) by its current market price.

Investopedia / Daniel Fishel

Understanding Bond Yields

A bond is essentially a loan to the bond issuer. They are considered safe investments because bond values don't change the same way stock prices do. They offer investors a reliable stream of income and provide bondholders with a fixed form of income.

Investors earn interest on a bond throughout the life of the asset and receive the face value of the bond upon maturity. Investors can purchase bonds for more than their face value, at a premium, or less than the face value, at a discount. Whichever they buy will change the yield they earn on the bond.

Bonds are rated by services approved by the Securities and Exchange Commission (SEC). Ratings go from “AAA,” which is low-risk investment grade, down to “D,” which means the bond is in default and carries the highest risk.

A bond investor's return is called the yield. There are a couple of. yield-related concepts, including the:

  • Coupon yield: This is the annual interest rate set when the bond is issued. It stays the same for the life of the bond.
  • Current yield: This depends on the bond’s price and its coupon payment. So if the bond’s price changes, its current yield changes too.

Formula and Calculation of a Bond Yield

The simplest way to calculate a bond yield is to divide its coupon payment by the bond's face value. This is called the coupon rate.

Coupon Rate = Annual Coupon Payment Bond’s Current Market Price \begin{aligned}&\text{Coupon Rate}=\frac{\text{Annual Coupon Payment}}{\text{Bond's Current Market Price}}\end{aligned} Coupon Rate=Bond’s Current Market PriceAnnual Coupon Payment

If a bond has a face value of $1,000 and makes interest or coupon payments of $100 per year, then its coupon rate is 10%: $100 ÷ $1,000.

Bond Yield vs. Bond Price

Price and yield are inversely related. This means that as the price of a bond goes up, its yield goes down. Conversely, as the yield goes up, the bond's price goes down.

If an investor buys a bond with a face value of $1,000 that matures in five years with a 10% annual coupon rate, the bond pays 10%, or $100, in interest annually. If interest rates rise above 10%, the bond's price will fall if the investor sells it.

Say the interest rate for similar investments rises to 12%. The original bond will still earn a coupon payment of $100, which would be unattractive to investors who can buy bonds that pay $120 as interest rates have risen. To sell the original $1,000 bond, the price can be lowered so that the coupon payments and maturity value equal a yield of 12%.

If interest rates fall, the bond's price would rise because its coupon payment is more attractive. The further rates fall, the higher the bond's price will rise. In either scenario, the coupon rate no longer has any meaning for a new investor. But if the annual coupon payment is divided by the bond's price, the investor can calculate the current yield and get an estimate of the bond's true yield.

Current Yield = Annual Coupon Payment Bond Price \text{Current Yield}=\frac{\text{Annual Coupon Payment}}{\text{Bond Price}} Current Yield=Bond PriceAnnual Coupon Payment

The current yield and the coupon rate are incomplete calculations for a bond's yield because they do not account for the time value of money, maturity value, or payment frequency, and more complex calculations are required.

Additional Bond Yield Calculations

As noted above, there are additional calculations that help investors better understand a bond's yield. These include the yield to maturity (YTM), bond equivalent yield (BEY), and effective annual yield (EAY).

Yield to Maturity (YTM)

A bond's yield to maturity is equal to the interest rate that makes the present value of all a bond's future cash flows equal to its current price. These cash flows include all the coupon payments and maturity value. Solving for YTM is a trial-and-error process that can be done on a financial calculator, but the formula is as follows:

YTM = [ C+ (FV - PV) ÷ t ] ÷ [ (FV + PV) ÷ 2 ]

Where:

  • C = Coupon Payment
  • FV = Face Value
  • PV = Present Value/Current Price
  • t = Years to Maturity

In the previous example, a bond with a $1,000 face value, five years to maturity, and $100 annual coupon payments is worth $927.90 to match a new YTM of 12%. The five coupon payments plus the $1,000 maturity value are the bond's six cash flows.

Finding the present value of each of those six cash flows with an interest rate of 12% will determine what the bond's current price should be.

Bond Equivalent Yield (BEY)

Bond yields are quoted as a bond equivalent yield, which adjusts for a bond coupon paid in two semi-annual payments. In the previous example, the bonds' cash flows were annual, so the YTM is equal to the BEY.

However, if the coupon payments were made every six months, the semi-annual YTM would be 5.979%. The BEY is a simple annualized version of the semi-annual YTM and is calculated by multiplying the YTM by two.

In this example, the BEY of a bond that pays semi-annual coupon payments of $50 would be 11.958% (5.979% X 2 = 11.958%). The BEY does not account for the time value of money for the adjustment from a semi-annual YTM to an annual rate.

Effective Annual Yield (EAY)

Investors can define a more precise annual yield given the BEY for a bond when considering the time value of money in the calculation. In the case of a semi-annual coupon payment, the effective annual yield would be calculated as follows:

E A Y = ( 1 + i n ) n 1 where: i = Nominal interest rate (as a decimal) n = Number of compounding periods per year \begin{aligned}&EAY=\left(1+\frac{i}{n}\right)^n-1\\&\textbf{where:}\\&i=\text{Nominal interest rate (as a decimal)}\\&n=\text{Number of compounding periods per year}\end{aligned} EAY=(1+ni)n1where:i=Nominal interest rate (as a decimal)n=Number of compounding periods per year

If an investor knows that the semi-annual YTM was 5.979%, they could use the previous formula to find the EAY of 12.32%. Because the extra compounding period is included, the EAY will be higher than the BEY.

Important

bond rating is a grade given to a bond that indicates its credit quality. The rating considers a bond issuer's financial strength or its ability to pay a bond's principal and interest in a timely fashion. The three most well-known bond rating agencies in the U.S. are Fitch Ratings, Standard & Poor’s Global Ratings, and Moody’s Investors Service.

Bond Yield Calculation Issues

Some factors skew the calculations in determining a bond's yield. In the previous examples, it was assumed that the bond had exactly five years left to maturity when it was sold, which is rare. The fractional periods can be defined, but the accrued interest is more difficult to calculate.

Assume a bond has four years and eight months to maturity. The exponent in the yield calculations can be turned into a decimal to adjust for the partial year.

However, this means that four months in the current coupon period have elapsed, with two remaining, which requires an adjustment for accrued interest. A new bond buyer will be paid the full coupon, so the bond's price will be inflated slightly to compensate the seller for the four months in the current coupon period that have elapsed.

Bonds can be quoted with a clean price that excludes the accrued interest or a dirty price that includes the amount owed to reconcile the accrued interest. When bonds are quoted in a system like a Bloomberg or Reuters terminal, the clean price is used.

Frequently Asked Questions (FAQs)

What Does a Bond's Yield Tell Investors?

A bond's yield is the return to an investor from the bond's interest, or coupon, payments. It can be calculated as a simple coupon yield or using a more complex method, like yield to maturity. Higher yields mean that bond investors are owed larger interest payments, but may also be a sign of greater risk. The riskier a borrower is, the more yield investors demand. Higher yields are often common with longer bonds.

Are High-Yield Bonds Better Investments Than Low-Yield Bonds?

Bond investment depends on an investor's circumstances, goals, and risk tolerance. Low-yield bonds may be better for investors who want a virtually risk-free asset, or who are hedging a mixed portfolio by keeping a portion of it in a low-risk asset. High-yield bonds may be better suited for investors who are willing to accept a degree of risk in return for a higher return.

Are High-Yield Bonds the Same as Junk Bonds?

Yes. High-yield bonds are known as junk bonds. Junk bonds have the lowest-rated corporate debt and may come with less secure foundations, and thus are riskiest. But they provide extra yield over safer alternatives.

How Do Investors Utilize Bond Yields?

Yields are used for more sophisticated analyses. Bonds of different maturities can be traded to take advantage of the yield curve, which plots the interest rates of bonds with equal credit quality but differing maturity dates.

The slope of the yield curve gives an idea of future interest rate changes and economic activity. They may also look at the difference in interest rates between different categories of bonds, holding some characteristics constant.

A yield spread is the difference between yields on differing debt instruments of varying maturities, credit ratings, issuer, or risk level, calculated by deducting the yield of one instrument from the other, such as the spread between AAA corporate bonds and U.S. Treasuries. This difference is most often expressed in basis points (bps) or percentage points.

The Bottom Line

Bond yield is the amount of return an investor will realize on a bond. The coupon rate and current yield are basic yield concepts used in understanding bond yields. There are many calculations involved in understanding bond yields from different perspectives, such as yield to maturity and bond equivalent yield. A bond rating is a grade given to a bond, indicating its credit quality and often the level of risk to the investor in purchasing the bond.

Article Sources
Investopedia requires writers to use primary sources to support their work. These include white papers, government data, original reporting, and interviews with industry experts. We also reference original research from other reputable publishers where appropriate. You can learn more about the standards we follow in producing accurate, unbiased content in our editorial policy.
  1. U.S. Securities and Exchange Commission. "Investor Bulletin: The ABCs of Credit Ratings."

  2. Financial Industry Regulatory Authority. "Understanding Bond Yield and Return."

  3. U.S. Securities and Exchange Commission. "Investor Bulletin: Fixed Income Investments - When Interest Rates Go Up, Prices of Fixed-Rate Bonds Fall."

  4. Financial Industry Regulatory Authority. "What to Know Before Saying Hi to High-Yield Bonds."

Take the Next Step to Invest
The offers that appear in this table are from partnerships from which Investopedia receives compensation. This compensation may impact how and where listings appear. Investopedia does not include all offers available in the marketplace.
Part of the Series
How to Invest with Confidence
Take the Next Step to Invest
The offers that appear in this table are from partnerships from which Investopedia receives compensation. This compensation may impact how and where listings appear. Investopedia does not include all offers available in the marketplace.

Related Articles