How it works
A PPF account has a 15-year term that can be extended in blocks of five years. You can put in between ₹500 and ₹1,50,000 in a financial year.
Interest is worked out every month on the balance after your deposit, then added to the account at the end of the financial year. A deposit made by the 5th of the month earns interest for that month.
That is why “once, by 5 April” earns the most: the whole year’s money is in the account for all twelve months. Depositing by the 5th of each month earns slightly less, because the money arrives gradually.
The government sets the rate every quarter. The default here is the rate in force for October to December 2026. Change it to see how a different rate would work out.
The formula
Year-end balance = (opening balance + deposits) + interest for the year
Interest for the year is the sum of each month’s interest: (balance after that month’s deposit) × rate ÷ 12. The rate is assumed to stay the same for all years, which will not be exactly true.
A worked example
Depositing ₹1,50,000 by 5 April every year at 7.1% for 15 years means you put in ₹22,50,000 and the account grows to about ₹40.7 lakh.
Frequently asked questions
What is the current PPF rate?
The rate is 7.1% a year for October to December 2026, unchanged from the previous quarter. It is announced every quarter and can change, so use the latest figure.
Is PPF interest taxable?
Under the current rules, deposits qualify for the Section 80C deduction (old regime), and the interest and the maturity amount are tax free. Rules can change, so check current law.
What happens if I miss a year’s deposit?
The account becomes inactive. You can revive it by paying a small penalty and the minimum for each missed year. This calculator assumes you deposit every year.
Why is my balance different from the passbook?
Rates change quarterly and this calculator uses one rate for all years. The exact dates of your deposits also matter.