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Accrued interest calculator
Work out the interest earned or owed between two dates: a month-end accrual on a note, a loan payoff, or the interest since the last coupon. Pick the day count your agreement uses and see the days, the daily amount and the total.
Loan or note
The stated (nominal) annual rate.
Use the day count your loan or note agreement specifies.
The accrued interest formula
The day count convention sets both the days and the year. For $100,000 at 6% from January 15, 2026 to March 31, 2026:
| Basis | Days | Year | Accrued interest |
|---|---|---|---|
| Actual/360 | 75 | 360 | $1,250.00 |
| Actual/365 | 75 | 365 | $1,232.88 |
| 30/360 (U.S.) | 76 | 360 | $1,266.67 |
The differences are small for one quarter and grow with the principal and the period, which is why the basis is written into the agreement. In Excel, =DAYS360(start, end) returns the 30/360 day count and =end − start the actual days.
Recording the accrual
| Account | Debit | Credit |
|---|---|---|
| Interest expense | 1,250.00 | |
| Interest payable | 1,250.00 |
The lender records the mirror image: interest receivable and interest income. For a loan with level payments, the loan amortization schedule splits each payment into interest and principal, and accrued interest is part of the month-end close checklist.
Accrued interest: questions
- How do you calculate accrued interest?
- Principal × annual rate × days ÷ days in the year, where the day count and the year length come from the loan's terms. $100,000 at 6% from January 15, 2026 to March 31, 2026 is 75 days; on an Actual/360 basis that's $1,250.00.
- What's the difference between Actual/360 and Actual/365?
- Both count the actual days elapsed, but Actual/360 divides by 360, so a day's interest is slightly larger and a full year accrues a little more than the stated rate. In the example, Actual/365 gives $1,232.88 against $1,250.00 for Actual/360.
- How does 30/360 count days?
- It treats each month as 30 days and the year as 360. The U.S. method, Excel's DAYS360 with FALSE or no third argument, turns a start date on the last day of a month into the 30th, and an end date on the last day of a month into the 1st of the next month if the start is before the 30th. The European method (30E/360) turns any 31st into the 30th.
- What's the journal entry for accrued interest?
- For the borrower: debit interest expense and credit interest payable. For the lender: debit interest receivable and credit interest income. When the interest is paid, the payable or receivable is cleared against cash.
- Is the end date counted?
- On the actual-day bases, the calculator counts the days from the start date up to the end date, without counting the end date itself, which is how interest between two payment dates is usually figured. Check your agreement if it says otherwise.
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Sources
Official documents read on November 5, 2026. Vendor facts are sourced on each listing.