A Public Provident Fund account takes ₹500 to ₹1,50,000 in a financial year. The first term is 15 years. After that, the account can be extended in blocks of 5 years. The PPF calculator will not go below ₹500, above ₹1.5 lakh, or under 15 years, because those inputs are outside the scheme.
The rate is set for a quarter, not for 15 years
For 1 October to 31 December 2026 the notified rate is 7.1% a year. That is the number loaded when the page opens. The Ministry of Finance reviews small-savings rates every quarter, so a 15-year illustration that keeps 7.1% all the way is a sketch. Change the rate if you want to see a lower or higher path. The deposited column will not move. The interest column will.
Why the month of the deposit matters
PPF interest is worked out on the lowest balance between the 5th of the month and the month end, then credited once a year. The calculator assumes the whole yearly deposit is in the account before the 5th of the first month, so it earns interest for that year. A deposit on the 6th misses that month. The estimate will then be higher than the passbook.
- Fifteen years is the shortest term the page will run.
- Twenty, twenty-five, and thirty years match the 5-year extension blocks.
- A year such as 16 still calculates, but it is not how an extension is granted.
Read the balance column year by year. The last row is the maturity only if every deposit lands on time and the rate you typed is the rate that is actually credited.