Irish Calculators
Saving & investing

Bond Price Calculator: Clean and Dirty Prices

Discount a bond's scheduled coupons and redemption using your chosen yield and convention. The result is a theoretical price, with no market quote, default model or irregular-coupon adjustment.

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Your numbers

%
Contractual coupon, not market yield.
Anchor for the regular coupon schedule. A month-end anchor keeps all coupon dates at month-end; otherwise the day is preserved, clipped when needed.
With more than one payment both modes compound. Check the convention used by the bond quote.
%
Compounded at coupon frequency.
Display currency only. Convert all inputs to this currency before calculation.
Your figures stay on this device.

How the calculation works

A regular bond price is the discounted value of future coupons and redemption. The calculator separates the dirty price, which includes accrued coupon, from the clean price, which removes the accrued portion between coupon dates.

Dirty price = sum[cash flow ÷ (1 + nominal annual yield/frequency)^fractional coupon periods]. For the optional one-payment simple convention, discount by 1 + yield/frequency × fractional periods instead. Clean price = dirty price − accrued coupon.

  1. Construct regular payments

    Generate equal coupons through maturity and add face-value redemption to the last one. Maturity must lie on the regular coupon grid.

  2. Discount from settlement

    Each cash flow is discounted by its remaining coupon-period time. The optional simple convention changes discounting only when a single payment remains.

  3. Separate accrued interest

    Accrued coupon is calculated from elapsed days within the current coupon period. Subtracting it from dirty price gives the clean price without changing the scheduled future receipts.

Worked example: Check Dirty price

Sample inputs demonstrate the method. They are not a forecast or product offer.

The first example has face value 1,000 and a 5% annual coupon discounted at a 5% annual yield on a coupon boundary. With matching coupon and yield, the dirty price equals face value: 1,000.

Face value
1000
Annual coupon rate (%)
5
Coupons per year
Annual
Settlement date
2026-01-01
Next coupon date
2027-01-01
Maturity date
2031-01-01
Discounting convention
Compound fractional coupon periods
Annual nominal yield (%)
5
Currency for all amounts
Euro (EUR)

Expected result

Dirty price
€1,000.00
Worked example: Check Dirty price

Sample inputs demonstrate the method. They are not a forecast or product offer.

Face value
1000
Annual coupon rate (%)
0
Coupons per year
Annual
Settlement date
2026-01-01
Next coupon date
2027-01-01
Maturity date
2027-01-01
Discounting convention
Compound fractional coupon periods
Annual nominal yield (%)
10
Currency for all amounts
Euro (EUR)

Expected result

Dirty price
€909.09

Understanding your result

Clean and dirty prices are two presentations of the same modelled bond value. Comparing one with a quotation on the other basis creates an apparent difference that is merely accrued interest.

The result assumes contractual payments occur as specified. Default, indexation, ex-coupon rules and irregular issue coupons are not reflected by changing the yield alone.

Questions you might have

What does the result include?

Discount a regular fixed-rate bond’s future coupons and redemption to estimate clean and dirty prices.

Which limits should I check?

No default risk, indexation, ex-coupon trading or irregular-issue coupons.

Choosing the right inputs

Face value
Enter the full nominal amount being valued. The output is for that holding, not automatically a market quote per 100 of face value.
Next coupon date
This date anchors the coupon grid. Settlement must be before it and on or after the previous regular coupon date.
Annual nominal yield
Enter nominal annual yield at the selected coupon frequency. Convert an effective annual yield first if necessary.

Common mistakes to avoid

  • Do not confuse the annual coupon rate with the yield used to discount payments.
  • Do not enter a per-100 price convention when the face amount represents a larger holding.

Assumptions to check

  • No default risk, indexation, ex-coupon trading or irregular-issue coupons.
  • All calculations run on your device. Figures are scenarios based on your inputs, not investment recommendations.

Sources and method

Read our calculation and testing approach.