This interest calculator date to date counts the exact days between two calendar dates and works out the interest for that period. Pick a start date and an end date, enter the principal and the yearly rate, and choose simple interest or monthly compounding. It reports the day count, interest for each day, the interest in total and what is owed at the end.
It is handy for private loans settled on a particular day, delayed payments, deposit interest for broken periods and any case where the period is not a neat number of months.
At a glance
- Simple interest by daysPrincipal × rate × days ÷ 36,500
- Day countFrom the first date to the second, 365 day year
- Example₹1 lakh at 9% for 73 days: ₹1,800
- Per day at 9%About ₹24.66 on ₹1 lakh
- Monthly compounding optionFor loans where unpaid interest is added monthly
- Leap yearsCounted day by day from the calendar
How the interest calculator date to date works
It subtracts the start date from the end date to count the days, the same way most lenders do: the first day is counted, the last day is not. Then it applies simple interest: principal × rate × days ÷ 365. For monthly compounding it grows the principal at the monthly rate for the fraction of months the days make up.
₹1,00,000 at 9% from 1 March to 13 May is 73 days, so the interest is ₹1,800, about ₹24.66 a day. ₹50,000 at 12% for 90 days earns ₹1,479. ₹2,00,000 at 18% for 291 days comes to ₹28,701.
Interest calculator in days: quick reference
| Principal | Rate a year | Days | Interest |
|---|---|---|---|
| ₹50,000 | 12% | 90 | ₹1,479 |
| ₹1,00,000 | 9% | 73 | ₹1,800 |
| ₹2,00,000 | 18% | 291 | ₹28,701 |
A quick mental check: interest for one day on ₹1 lakh at R% is about R × 2.74 rupees. At 12%, that is about ₹33 a day.
Counting days the way lenders do
- Exclusive end date: money lent on 1 March and repaid on 13 May is 73 days. Some agreements count both ends; add one day in that case.
- 365 or 360: Indian banks normally use 365, also in leap years for most products. A few contracts use 360, which gives slightly more interest.
- Month counting: some informal loans count whole months only, so 1 March to 13 May would be charged as 2 or 3 months. Agree the method in writing.
Common uses
- Settling a private loan on an exact date.
- Interest on delayed payment under a contract. For tax, the GST interest calculator follows the GST rules.
- Overdraft periods, though the OD interest calculator is set up for that.
- Broken period interest on the first EMI of a new loan.
- Checking a deposit's interest for an odd number of days.
Simple or compound for your dates
For periods under a year, simple and compound interest give close figures. Over longer spans, or where an agreement says unpaid interest is added monthly, pick the compound option. To compare against daily compounding, use the daily compound interest calculator. For a fixed number of years, the general interest calculator and the simple interest calculator are quicker.
Writing interest into a private agreement
A clear written note avoids disputes later. It should state the amount lent, the date, the yearly rate, whether interest is simple or compounded, how days are counted and when interest is to be paid. If interest is due monthly but may be held back, say whether held back interest earns interest. Both sides should sign and keep a copy. With those details fixed, anyone can recompute the figure with this tool on settlement day.
Frequently asked questions
How do I calculate interest between two dates?
Count the days between them, then multiply principal × rate × days ÷ 36,500. The tool does the day count itself.
Is the first day or last day counted?
Most lenders count the first day and not the last. If your agreement counts both, add one day.
What is the interest on ₹1 lakh for 73 days at 9%?
₹1,800 as simple interest.
Do banks use 365 or 360 days?
Indian banks normally use 365 days. Some contracts use 360, which gives slightly higher interest.
Will this interest calculator in days work for a deposit?
Yes, for simple interest. For an FD that compounds quarterly, use the FD calculator instead.
Does it handle leap years?
Yes. It counts actual calendar days between the two dates.