Bond Duration Convexity Calculator
Free Bond duration convexity Calculator for bonds. Enter your numbers to see returns, costs, and optimized scenarios instantly.
Formula
Mac. Duration = ฮฃ(t ร PV(CFt)) / Price | Mod. Duration = Mac. Duration / (1 + y/n)
Macaulay duration is the weighted average time of cash flows, where weights are present values. Modified duration adjusts for yield compounding and directly measures price sensitivity to yield changes. Convexity adds a second-order correction for large rate movements.
Worked Examples
Example 1: 10-Year Corporate Bond
Problem: A corporate bond has a face value of $1,000, 6% annual coupon rate (semi-annual), 10 years to maturity, and YTM of 5%. Calculate duration and convexity.
Solution: Face Value = $1,000 | Coupon = 6% (semi-annual = $30 every 6 months)\nYTM = 5% (2.5% per period) | Periods = 20\nBond Price โ $1,077.95\nMacaulay Duration โ 7.66 years\nModified Duration โ 7.47\nConvexity โ 66.73
Result: Price = $1,077.95 | Mac. Dur. = 7.66 yrs | Mod. Dur. = 7.47 | Convexity = 66.73
Example 2: Rate Change Impact Analysis
Problem: Using the bond above, estimate the price change if yields increase by 1%.
Solution: Modified Duration = 7.47 | Convexity = 66.73 | Price = $1,077.95\nDuration effect: -7.47 ร 0.01 ร $1,077.95 = -$80.52\nConvexity effect: 0.5 ร 66.73 ร 0.01ยฒ ร $1,077.95 = +$3.60\nTotal change โ -$76.92 (-7.14%)\nNew price โ $1,001.03
Result: Price drops ~$76.92 (-7.14%) | Duration alone overestimates decline by $3.60
Frequently Asked Questions
What is bond duration and why does it matter?
Bond duration is a measure of the sensitivity of a bond's price to changes in interest rates. Macaulay duration, developed by Frederick Macaulay in 1938, represents the weighted average time until a bond's cash flows are received, measured in years. Modified duration adjusts the Macaulay duration for the yield per period and directly estimates the percentage price change for a one percent change in yield. For example, a bond with a modified duration of 5 would decrease approximately 5% in price for every 1% increase in yield. Duration is critical for portfolio managers who need to manage interest rate risk, match asset and liability durations (immunization), and compare bonds with different maturities and coupon rates.
What is convexity and how does it relate to duration?
Convexity is the second-order measure of a bond's price sensitivity to interest rate changes. While duration provides a linear approximation of price change, convexity captures the curvature in the price-yield relationship. Duration alone underestimates the price increase when yields fall and overestimates the price decrease when yields rise. Convexity corrects this by adding a quadratic term to the price change estimate. Higher convexity means the bond price will rise more when yields fall and decline less when yields rise, making it a desirable property. The total estimated price change combines both: ฮP โ -Modified Duration ร ฮy ร P + 0.5 ร Convexity ร (ฮy)ยฒ ร P. Convexity is particularly important for large yield changes where the linear duration approximation becomes inaccurate.
How do coupon rate and maturity affect duration?
Duration is influenced by three main factors: coupon rate, maturity, and yield to maturity. A higher coupon rate reduces duration because more cash flow is received earlier, reducing the weighted average time. A longer maturity generally increases duration because cash flows extend further into the future. However, for very long-term premium bonds, duration can plateau. A higher yield to maturity reduces duration because the present value of distant cash flows decreases more steeply. A zero-coupon bond has the simplest case: its Macaulay duration equals its maturity since there is only one cash flow at maturity. For all coupon-paying bonds, the Macaulay duration is always less than the maturity. Understanding these relationships is essential for constructing bond portfolios with target duration profiles.
What is the difference between Macaulay and modified duration?
Macaulay duration and modified duration are related but serve different purposes. Macaulay duration is measured in years and represents the weighted average time to receive all cash flows from a bond, where weights are the present values of each cash flow as a fraction of the total bond price. It answers the question of when, on average, you receive your money back. Modified duration is derived from Macaulay duration by dividing by (1 + y/n), where y is yield and n is compounding frequency. It is a pure sensitivity measure without time units, indicating the approximate percentage change in price for a 1% yield change. For zero-coupon bonds, Macaulay duration equals maturity, while modified duration is slightly less. Modified duration is more commonly used in practice for risk management because it directly translates yield changes into price changes.
What formula does Bond Duration Convexity Calculator use?
The formula used is described in the Formula section on this page. It is based on widely accepted standards in the relevant field. If you need a specific reference or citation, the References section provides links to authoritative sources.
Is Bond Duration Convexity Calculator free to use?
Yes, completely free with no sign-up required. All calculators on NovaCalculator are free to use without registration, subscription, or payment.