Free bond duration calculator — compute Macaulay duration, modified duration, and estimated price change for interest-rate moves on any coupon bond.
Bond duration measures a bond\u0027s sensitivity to interest-rate changes. Macaulay duration expresses the weighted-average time to receive cash flows, while modified duration translates that into an approximate percentage price change for a 1% shift in yield. Together they are the most widely used risk metrics in fixed-income analysis.
Our Bond Duration Calculator computes both Macaulay and modified duration, then shows the estimated price impact for a user-specified yield change. Enter face value, coupon rate, yield, maturity, and frequency to instantly see how rate movements could affect your bond position. Modified duration quantifies how much a bond price changes for every 1% shift in interest rates, making it the primary metric for interest-rate risk management. This calculator computes both Macaulay duration, which measures the weighted average time to receive cash flows, and modified duration, which translates that into price sensitivity. Investors who manage bond portfolios or ladder maturities need this information to balance yield against risk.
Managing interest-rate risk is central to bond investing. Duration tells you how much a bond price is likely to move when rates change. Portfolio managers duration-match assets and liabilities, traders use duration to size hedges, and individual investors use it to compare the risk profiles of different bonds. Without duration, you cannot quantify or control your exposure to the single biggest risk factor in fixed income.
Macaulay Duration = (1/P) × Sum[t × C/(1+y)^t, t=1..n] + n × F/(1+y)^n, where P = bond price, C = coupon per period, y = yield per period, F = face value, n = total periods. Modified Duration = Macaulay Duration / (1 + y/k), where k = compounding periods per year. Price Change ≈ -Modified Duration × Δy × Price.
Result: Macaulay 6.17 yrs / Modified 6.05
A 7-year, 5% coupon bond priced to yield 4% (semi-annual) has a Macaulay duration of about 6.17 years and a modified duration of 6.05. This means a 1% rise in yields would cause the price to drop approximately 6.05%, or about $66 on a $1,090 bond.
Duration is the cornerstone metric for managing interest-rate risk. Originally conceived by Frederick Macaulay in 1938, it measures the present-value-weighted average maturity of a bond. A higher duration means greater sensitivity to rate changes. In today's markets, every fixed-income portfolio report includes duration alongside yield and credit quality.
Macaulay duration is measured in years and answers the question: "On average, when do I get my money back?" Modified duration adjusts Macaulay for the compounding effect and expresses sensitivity as a percentage price change per 1% yield move. Effective duration is used for bonds with embedded options (like callable bonds) and requires scenario pricing rather than a closed-form formula.
Institutional investors match the duration of assets and liabilities to immunize against rate risk. For example, a pension fund with liabilities of duration 12 will build a bond portfolio with the same duration. When rates move, asset and liability values change by roughly the same amount, preserving the funded ratio. Individual investors can similarly use duration to choose bonds that align with their time horizon and risk tolerance.
Macaulay duration is the weighted-average time (in years) until a bond's cash flows are received, using present values as weights. Modified duration divides Macaulay duration by (1 + y/k) to express interest-rate sensitivity as a percentage price change per 1% yield shift. Macaulay answers "when," modified answers "how much."
Multiply modified duration by the yield change and by the current price, then negate the result. For example, if modified duration is 6 and yields rise 0.5%, the price drops approximately 6 × 0.005 × Price = 3% of the current price. For large rate moves, add a convexity correction for better accuracy.
A higher coupon means larger cash flows arrive earlier, pulling the weighted-average maturity closer to the present. Because duration weights each payment by its present value, front-loaded cash flows reduce the average time and therefore the duration.
Duration provides a linear approximation that works well for small yield changes (up to about 50 basis points). For larger shifts, the estimate becomes less accurate because the price-yield relationship is convex, not linear. Add a convexity adjustment to improve accuracy for big rate moves.
Portfolio duration is the market-value-weighted average of the durations of all bonds in the portfolio. If half your capital is in 3-year duration bonds and half is in 7-year duration bonds, your portfolio duration is approximately 5 years, meaning a 1% rate rise would reduce the portfolio value by about 5%.
Floating-rate bonds reset their coupons periodically, so their duration is very short — typically close to the time until the next reset date. This is why floaters exhibit minimal price sensitivity to interest-rate changes compared to fixed-rate bonds of similar maturity.