Interest Calculator
Principal, rate, and required start & end dates — get exact-day interest and maturity for simple or compound interest.
Interest inputs
Start date and end date are required. Interest is calculated for the exact day count between them (actual / 365).
Interest earned
₹7,500
365 days · simple
Maturity amount
₹1,07,500
Principal + interest
Duration
365 days
1.000 years
Daily rate
0.0205%
Annual rate ÷ 365
From 2026-08-28 to 2027-08-28, ₹1,00,000 at 7.5% p.a. (simple) earns ₹7,500.
About Interest Calculator
Calculate simple or compound interest between a required start date and end date using actual/365 day count.
How it works
Enter principal, rate, start date and end date. Choose simple or compound (with frequency). Read interest and maturity.
Practical tips
Always set both dates — duration drives the result. Use compound for multi-year deposits.
Important to know
Banks may use different day conventions or TDS.
Frequently Asked Questions
- Are start and end dates required?
- Yes. Both start date and end date are mandatory — interest is computed from the exact day count between them.
- How is the duration calculated?
- We use actual calendar days between the dates and convert to years as days ÷ 365 (actual/365).
- Simple vs compound interest?
- Simple uses P × R × T / 100. Compound uses periodic compounding (yearly, quarterly, monthly or daily) over the same day-based tenure.
- Can the end date be before the start date?
- No. End date must be on or after the start date, or the calculator shows an error.
- Is this the same as a bank FD quote?
- It’s a transparent day-count illustration. Bank FDs may use different day conventions, compounding or TDS.