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Duration and convexity calculator

Compare a duration-only estimate, a duration-and-convexity estimate and the exact price change for the same regular coupon bond.

Omni Finance AcademyBy Omni Finance Academy
Bond price
100
Macaulay duration
4.4854 years
Modified duration
4.376
Convexity
22.6123
Duration estimate
-2.188 %
Duration + convexity estimate
-2.1598 %
Exact repricing change
-2.16 %
91.68100.5109.2357Annual yield (%)Bond price91.68100.5109.2357Annual yield (%)Bond price
Price across nearby yields

The same regular bond is repriced at each displayed annual yield; face value and cash flows stay fixed. This is an illustrative example.

View the chart values
Price across nearby yields: underlying values
SeriesAnnual yield (%)Bond price
Bond3109.22218
Bond3.5106.82592
Bond4104.49129
Bond4.5102.21655
Bond5100
Bond5.597.839981
Bond695.734899
Bond6.593.683204
Bond791.683395

A local estimate of a price change

Modified duration supplies the linear part of the estimate. Convexity adds curvature. Both measures are calculated from the bond’s discounted regular cash flows, using the coupon frequency shown in the inputs. The exact comparison reprices those same cash flows at the shifted yield.

Enter the yield change in basis points

A change of 50 basis points is 0.005 in decimal yield, or half a percentage point. A positive change raises the yield. A negative change lowers it. The shifted yield must remain within the regular-bond model’s nonnegative-yield range.

ΔPP≈−DmodΔy+12C(Δy)2\frac{\Delta P}{P}\approx-D_{mod}\Delta y+\frac{1}{2}C(\Delta y)^2

Duration and convexity use the same yield convention. The yield change is a decimal inside the formula.

Use the comparison to learn the approximation

For a small yield move, the estimates usually sit close to exact repricing. For a larger move, neglected higher-order terms can matter. Embedded options, changing cash flows and nonparallel yield-curve changes require different modelling assumptions; this tool holds the regular cash flows fixed.

Further references