Accrued Interest Calculator
Accrued interest between coupon dates, across day count conventions. The convention is not a detail: actual/360 and 30/360 give materially different answers on the same bond.
Also called: bond accrued interest, clean vs dirty price.
$17,876.71 accrued over 87 days on the actual/365 convention. A buyer pays this on top of the clean price, making the dirty price the clean price plus this amount. The convention alone moves the figure by $248.29.
This is what the calculation gives for the numbers you entered. It is an estimate, not advice, and it knows nothing about your situation beyond those numbers. Rules for United States change on a published schedule; the effective date is shown on every rule-based tool.
How this is calculated
Between coupon dates, interest accrues to the seller and the buyer pays it as part of the settlement. The day count convention decides how much: actual/360 counts real days over a 360 day year and produces the largest figure, 30/360 assumes every month has thirty days, and actual/365 counts real days over a real year. Which applies is set by the instrument, not chosen. Quoted bond prices are clean, meaning they exclude accrued interest, and the amount actually paid is the dirty price.
the coupon prorated by days elapsed over days in the period, on the stated convention- d
- Days elapsed
- D
- Days in the period
Method and limits
What it assumes
- A regular coupon period with no stub.
What it deliberately does not model
- Actual/actual conventions vary in their treatment of leap years and are not modelled here.
Formula version 1.0.0 · definition 1.0.0 · United States · Report a problem with this calculator
Frequently asked questions
- What is the difference between clean and dirty price?
- Clean excludes accrued interest and is what gets quoted. Dirty includes it and is what you pay. Quoting clean makes prices comparable across dates.