Bond Yield Calculator

The inverse relationship between bond prices and yields is the most fundamental concept in fixed income investing, and it confuses nearly every new investor. Here is the core logic: a bond's coupon payment is fixed in dollar terms at issuance. If you own a $1,000 bond paying $50 per year (a 5% coupon), that $50 payment never changes. But if market interest rates rise to 6% after you buy the bond, new bonds are now paying $60 per year. Your bond, still paying only $50, is now less attractive. For your bond to compete, its price must fall until the $50 annual payment represents a 6% yield on the new (lower) price.

The reverse also holds: when rates fall, existing bonds with higher coupons become more valuable. A bond paying 6% when new bonds only pay 4% is highly desirable. Its price rises until buyers are effectively earning 4% on their purchase — eliminating the yield advantage. This mechanic is why long-term bond funds fell 20–30% in 2022 when the Federal Reserve rapidly raised rates. The bonds in those funds were paying old, lower coupons, and their prices had to fall dramatically to compete with new higher-rate issuances.

Current yield is the simplest measure: it divides the annual coupon payment by the current market price. A $1,000 bond paying $50 per year purchased at $950 has a current yield of 5.26% ($50 / $950). This is useful for income-focused investors comparing how much cash a bond generates relative to its cost, but it ignores what happens at maturity.

Yield to maturity (YTM) is more complete. It accounts for the coupon payments, the current price, and the gain or loss when the bond matures at face value. If you buy the $950 bond above, you will receive $50/year in coupons plus a $50 capital gain when the bond matures at $1,000. YTM captures both components — in this case producing a yield higher than the current yield. Conversely, if you pay $1,050 for the same bond, you will receive $50/year in coupons but lose $50 at maturity, producing a YTM below the current yield.

For most investment decisions, YTM is the correct metric to use for comparison. It normalizes all bonds — regardless of coupon, price, or remaining maturity — to a single comparable annual return figure. Bond screeners, broker platforms, and financial advisors all use YTM as the standard measure of a bond's total expected return.

Duration measures how sensitive a bond's price is to changes in interest rates. Specifically, Macaulay duration expresses the weighted average time (in years) until you receive all of the bond's cash flows — coupons plus final principal. A bond with a Macaulay duration of 7 years will lose approximately 7% of its price if interest rates rise by 1 percentage point, and gain approximately 7% if rates fall by 1 percentage point.

This is why long-term bonds are much riskier than short-term bonds in environments where rates might rise. A 30-year Treasury bond might have a duration of 18–20 years — meaning a 1% rate increase produces an 18–20% price decline. A 2-year Treasury note has a duration closer to 1.9 years, so the same 1% rate move causes only a 1.9% price change. Zero-coupon bonds have the highest duration of any bond (equal to their maturity) because all cash flow comes at the end, making them extremely sensitive to rate changes.

Understanding duration helps you build a bond portfolio matched to your time horizon and rate outlook. If you plan to hold bonds to maturity, price volatility is largely irrelevant — you will receive the promised cash flows regardless of interim price moves. If you might need to sell before maturity, shorter-duration bonds protect your capital from rate-driven price declines.