Compute the daily interest on a loan or balance.
Please do not make financial decisions based on these results.
What is the Interest Per Day Calculator?
Compute the daily interest on a loan or balance. To use the Interest Per Day Calculator, enter balance, annual rate, days; it returns interest per day, interest over the days, and shows them instantly as you type.
Where the Interest Per Day Calculator fits
Compute the daily interest on a loan or balance. The main figure it returns is the Interest per day, worked out from the values you enter.
It belongs with the other loans & debt tools. If you are comparing options or checking a result from another angle, try the Loan Interest Calculator, Mortgage Interest Calculator or the Credit Card Interest Calculator.
How to use the Interest Per Day Calculator
- Enter your numbers. The inputs are Balance ($), Annual rate (%), Days. Take the rate and term from your loan offer. Fees and the rate type change the result. Fields marked optional can stay at zero.
- Read the result. The highlighted box gives the Interest per day, and the cards below show Interest over the days. Tables and charts break it down further.
- Test other scenarios. Results update as you type. Change one value at a time to see what drives the answer, and press Reset to go back to the defaults.
Formula and how it works
Example with real numbers
Here is the Interest Per Day Calculator using the default values shown in the calculator above:
Inputs
| Balance ($) | 25,000 |
|---|---|
| Annual rate (%) | 6.8 |
| Days | 45 |
Results
| Interest per day | $4.66 |
|---|---|
| Interest over the days | $209.59 |
With these inputs the calculator returns Interest per day: $4.66. Change any value in the calculator to see how the result moves.
What if you change one input?
Sensitivity check: raising Balance ($) from 25,000 to 30,000 (about 20% higher) and leaving everything else as in the example above changes the results like this:
| Result | Example | After the change | Change |
|---|---|---|---|
| Interest per day | $4.66 | $5.59 | +20% |
| Interest over the days | $209.59 | $251.51 | +20% |
The input that moves the result most is the one to check twice. Change it in the calculator above to test your own case.
What the results tell you
The results panel of the Interest Per Day Calculator reports Interest per day and interest over the days. Compare these figures while changing one input at a time, and use the related calculators below to look at the same situation from another angle.
Method and limits. This calculator applies the formula in the section above to your inputs, in your browser; nothing you enter is stored on our servers. Your lender’s offer is the final word: fees, rate type and rounding differ between lenders. It is for information, not financial, tax or legal advice.
Frequently asked questions
Why does daily interest matter?
Per-diem interest is used for payoff quotes and credit cards.
Can I enter the term in years and months?
Yes. Enter years and months together, for example 6 years and 2 months.
How can I pay off a loan faster?
Pay more than the required amount, add extra yearly or one-time payments, or switch to biweekly payments. Make sure extra payments go to principal.
Are the results guaranteed?
No. Results depend entirely on the numbers you enter and the formulas shown on this page. Please do not make financial decisions based on them alone; confirm important figures with a licensed professional.
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