Enter your bond’s nominal value, current price, coupon rate, coupon frequency, settlement date and maturity date to calculate effective duration instantly. Works for plain-vanilla and option-sensitive fixed income instruments. Free, no signup.
The face value of the bond — the amount the issuer repays at maturity. Most government and corporate bonds have a nominal of $1,000, £100 or €1,000 depending on the market. Nominal value determines the coupon payment amount and the principal cash flow at maturity.
The date the bond repays its nominal value. Together with the settlement date this sets the bond’s remaining life — the span over which the effective duration calculation evaluates price sensitivity. Longer remaining life produces higher effective duration, all else equal.
The date on which the bond transaction settles, typically one to two business days after the trade date. The calculator uses this to identify the exact number of remaining coupon periods and the accrued interest at the calculation date. For a bond already held, enter today’s date.
The bond’s market price expressed as a percentage of nominal value. Enter the clean price — the market-quoted price excluding accrued interest. A price of 96.50 means the bond trades at 96.5% of face value.
The calculator derives the bond’s Yield to Maturity from this price and then applies small upward and downward yield shifts internally to compute how the bond’s price would change under each scenario. These shifted prices are used to calculate effective duration.
The annual interest rate the bond pays as a percentage of nominal value. Along with coupon frequency and the coupon schedule derived from the maturity date, this determines the cash flows the bond generates in each yield scenario. The calculator re-evaluates these cash flows under shifted yields to model how the bond’s price responds to rate changes.
How often the bond makes coupon payments per year — annual, semi-annual or quarterly. This determines the coupon schedule and the size of each individual payment. Most government bonds pay semi-annually. Match this input to the bond’s actual payment terms.
Unlike the Bond Duration Calculator, which computes Macaulay and Modified Duration analytically from the fixed cash flow schedule, this calculator measures effective duration numerically. It does this in three steps:
Step 1 — Derive the base YTM from the current price, nominal value, coupon schedule and settlement date.
Step 2 — Reprice the bond at two shifted yields: the base YTM minus a small shift (typically 10 basis points) to get P↓, and the base YTM plus the same shift to get P↑.
Step 3 — Apply the effective duration formula:
Effective Duration = (P↓ − P↑) / (2 × P₀ × Δy)
Where P₀ is the base price (dirty), P↓ is the price at lower yield, P↑ is the price at higher yield, and Δy is the yield shift in decimal form.
For a plain-vanilla fixed-rate bond with no embedded options, effective duration equals Modified Duration — the two calculators produce the same result. The distinction matters when the bond’s actual market price at a shifted yield differs from the analytically repriced value — which occurs when option exercise behaviour changes the expected cash flows.
A callable corporate bond:
| Input | Value |
|---|---|
| Nominal value | $1,000 |
| Maturity date | 15 October 2035 |
| Settlement date | 15 April 2026 |
| Current price (clean) | 99.50 |
| Coupon rate | 5.5% |
| Coupon frequency | Semi-annual |
Base YTM implied by a price of 99.50 on this bond: approximately 5.57%.
The calculator applies a 10 basis point shift in each direction:
| Scenario | Yield | Repriced clean price |
|---|---|---|
| Yield falls 10 bps | 5.47% | 100.56 |
| Base | 5.57% | 99.50 |
| Yield rises 10 bps | 5.67% | 98.45 |
Dirty price at base (adding accrued interest): $1,000.63
Effective Duration = ($1,005.60 − $984.50) / (2 × $1,000.63 × 0.001) = $21.10 / $2.001 = 10.54
For a standard bond of this maturity and coupon, Modified Duration would be approximately 7.8. The higher effective duration figure reflects the callable bond’s specific price behaviour — the calculator is detecting that the bond’s price responds more sensitively to yield changes than a plain-vanilla bond would.
Note: if your callable bond’s prices are sourced from an OAS model (which accounts for the call option directly), you can use those prices in the Bond Duration Calculator with the P↑ and P↓ inputs for a fully option-adjusted result. See the full guide below for more detail.
| Bond type | Do the two calculators agree? |
|---|---|
| Plain-vanilla fixed coupon | ✅ Results are identical |
| Zero-coupon bond | ✅ Results are identical |
| Callable bond near call price | ❌ Effective Duration captures price compression |
| Putable bond near put price | ❌ Effective Duration captures price floor |
| MBS / ABS | ❌ Effective Duration accounts for prepayment |
| Floating-rate note | ❌ Effective Duration measures reset risk |
If the two calculators give the same result for your bond, the bond’s price behaviour is consistent with fixed cash flows — no optionality is affecting the price-yield relationship. If the results differ significantly, the bond has option-sensitive characteristics that Modified Duration cannot capture.
Effective Duration is expressed in years and interpreted identically to Modified Duration: a result of 10.54 means the bond’s price changes by approximately 10.54% for a 1% parallel shift in yields.
| Effective Duration | Typical instrument |
|---|---|
| 0 – 1 | Floating-rate notes between resets, very short maturities |
| 1 – 4 | Short-term callable bonds, short-maturity MBS |
| 4 – 8 | Medium-term callable corporates, agency pass-throughs |
| 8 – 14 | Long callable bonds, long MBS, CMBS |
| Negative | IO strips, certain inverse floaters |
Negative effective duration means the bond’s price rises as yields increase — the opposite of normal behaviour. This occurs in instruments such as mortgage interest-only (IO) strips, where higher rates reduce prepayments and extend the cash flow stream, increasing value despite the higher discount rate.
Both calculators derive Yield to Maturity from the price you enter. The difference is in how they apply that yield to compute duration. The Bond Duration Calculator computes Macaulay and Modified Duration analytically from the fixed coupon schedule. This calculator measures effective duration by repricing the bond at two shifted yields and observing the actual price response — a numerical method that captures any non-linearity in the price-yield relationship.
Use this calculator when you suspect the bond’s price behaviour deviates from the simple fixed cash flow model — particularly for callable bonds, putable bonds, and any bond with structural features that might change the expected cash flow timing. For plain-vanilla government bonds and standard fixed-rate corporate bonds with no optionality, both calculators give the same result and either is appropriate.
It means the bond’s price is more sensitive to yield changes than a standard fixed cash flow model predicts. This can occur for callable bonds where the call option creates asymmetric price behaviour, or for deeply discounted bonds where small yield changes produce large relative price moves. A significant difference between the two metrics is a signal to investigate the bond’s structural features more closely.
The bond’s price rises when yields increase rather than falling. This occurs in mortgage interest-only strips (where higher rates slow prepayments and extend cash flows, increasing value) and certain structured products where the embedded option dominates normal bond price behaviour. Standard callable and putable corporate bonds do not exhibit negative effective duration under normal market conditions.
For basic pass-through MBS, this calculator provides a reasonable estimate of effective duration based on the bond’s current price and coupon characteristics. For precise MBS analysis, the most accurate approach uses prices generated by a prepayment model at shifted yields, which accounts for how borrower refinancing behaviour changes at different rate levels. The full guide below covers this in detail.
For a complete professional explanation of why effective duration is necessary, negative convexity mechanics, how OAS models generate option-adjusted prices, key rate duration and institutional ALM applications:
👉 Effective Duration Explained — Negative Convexity, OAS and Professional Applications
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