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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.

₹
%
Day count convention
Accrued interest
₹17,877

₹17,877 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.

Accruing per day
₹205
Full coupon amount
₹37,500
On actual/360
₹18,125
On 30/360
₹18,125
Spread between conventions
₹248
Convention
actual/365
On clean and dirty price
the clean price plus this amount.
How this is calculated
Method and background

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 India 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

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

eighty-seven days into a semiannual coupon

Face value
₹10,00,000
Coupon rate
7.5%
Days since the last coupon
87
Day count convention
Actual/365
Coupons a year
2

Accrued interest₹17,877

37,500 x 87 / 182.5

Open this example

the day after a coupon accrues nothing

Face value
₹10,00,000
Coupon rate
7.5%
Days since the last coupon
0
Day count convention
Actual/365
Coupons a year
2

Accrued interest₹0

boundary

Open this example

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 · India · 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.