Bond Equivalent Yield (BEY)

Yield & Income

Updated Apr 2026 • Has calculator

Converts a semi-annual yield to an effective annual yield using compound interest.

What is Bond Equivalent Yield?

Bond equivalent yield converts the semi-annual yield of a bond into its effective annual yield by compounding. Because US bonds typically pay coupons semi-annually, the quoted YTM is already a semi-annual rate doubled (not compounded) to produce the nominal annual rate. BEY instead applies compound arithmetic, giving the true effective annual yield: BEY = (1 + semiYield)² − 1. For example, a 4% semi-annual yield compounds to an 8.16% annual effective yield, not 8.00%. BEY is used to compare semi-annual bonds with annually compounding instruments such as European bonds, money market rates, and swap rates.

Formula

BEY = (1 + SemiYield%)² − 1 (expressed as a percent)

Worked Example

Annual compounding comparison

Step 1 Semi-annual coupon rate: 4% per half-year (nominal annual = 8%)

Step 2 BEY = (1 + 4/100)² − 1

Step 3 BEY = 1.04² − 1 = 1.0816 − 1 = 0.0816 = 8.16%

Step 4 → This semi-annual bond is equivalent to 8.16% compounded annually

Step 5 → A European annual-pay bond must yield > 8.16% to match it

Source: CFA Institute — Fixed Income Analysis, 3rd ed., Ch. 3 (2023-01-01)

Calculate Bond Equivalent Yield

Semi-Annual Yield (%)

Yield per semi-annual period in percent (e.g. 4 = 4%/half-year)

Bond Equivalent Yield

—

Not investment advice.

How to Interpret Bond Equivalent Yield

< 3

< 3%: Low BEY — short-term or high-quality government bond

3 – 6

3–6%: Moderate — typical investment-grade corporate bond range

6 – 9

6–9%: High — below-investment-grade or high-yield territory

> 9

> 9%: Very high — distressed or speculative-grade bonds

📚 Bond Basics — Complete the path

Sources