PPF Rules and How Interest Is Calculated, A Simple Guide for Investors

You opened a Public Provident Fund account because it offers tax‑free returns backed by the Government of India. Every year you deposit money, and every year interest gets added. But the interest is not calculated on your full balance the way a fixed deposit works. There is a specific rule about the 5th of the month that can change how much you earn. This guide explains the calculation, the key rules around deposits and withdrawal, and how to project your maturity amount with a free browser calculator. This is for informational purposes only and is not financial advice.

How PPF interest is actually calculated

The government sets a PPF interest rate every quarter, and the interest is compounded annually. But the amount on which interest is calculated is not simply your year‑end balance. It is the minimum balance in your account between the 5th and the last day of every month.

This means: if you make a lump‑sum deposit of Rs 1.5 lakh on April 20, the interest for April is calculated on the balance as it stood between April 5 and April 30. Since your balance before April 20 was lower, you lose interest on that Rs 1.5 lakh for the entire month of April. To earn interest for the full month, the money needs to be in the account by the 5th of that month.

The PPF calculator applies this logic by assuming the entire yearly deposit is made before April 5. This is the best strategy for maximising your returns. If you deposit after the 5th, your actual interest for that year may be slightly lower than what the calculator shows.

The key PPF rules in plain language

• Tenure: A PPF account matures after 15 financial years from the date of opening. The 15‑year clock starts from the end of the financial year in which the account was opened. You can extend the account indefinitely in blocks of 5 years with or without fresh contributions.
• Minimum and maximum deposit: You must deposit at least Rs 500 per financial year to keep the account active. The maximum you can deposit is Rs 1.5 lakh per financial year. Deposits can be made in a lump sum or in instalments across the year.
• Tax treatment: Deposits up to Rs 1.5 lakh per year qualify for deduction under Section 80C of the Income Tax Act. The interest earned is tax‑free. The maturity amount is also tax‑free. PPF falls under the Exempt‑Exempt‑Exempt (EEE) tax category.
• Partial withdrawal: You can make a partial withdrawal every year starting from the 7th financial year. The maximum you can withdraw is the lower of 50% of the balance at the end of the 4th preceding year, or 50% of the balance at the end of the immediately preceding year. Only one withdrawal is allowed per financial year.
• Loan against PPF: You can take a loan against your PPF balance between the 3rd and 6th financial years. The maximum loan is 25% of the balance at the end of the second preceding financial year. Interest on the loan is slightly higher than the PPF rate and must be repaid within 36 months.
• Inactive accounts: If you fail to deposit the minimum Rs 500 in a year, the account becomes inactive. It can be reactivated by paying a penalty of Rs 50 per inactive year and depositing the minimum amount for each missed year.

How to project your maturity amount

Open the PPF calculator in your browser. Enter the yearly deposit amount, anywhere between Rs 500 and Rs 1,50,000. The calculator defaults the interest rate to the current government‑notified rate; you can update it if a new rate is announced. It shows the year‑wise balance, the total amount you deposited over 15 years, the total interest earned, and the maturity amount.

For example, a yearly deposit of Rs 1.5 lakh at 7.1% interest grows to roughly Rs 40.5 lakh after 15 years. Out of that, Rs 22.5 lakh is your own contribution and Rs 18 lakh is interest. All of it is tax‑free in your hands. The calculation runs inside your browser; your investment amounts never leave your device.

One thing about extending PPF beyond 15 years

If you extend without fresh contributions, your existing balance continues to earn interest at the prevailing PPF rate, and you can withdraw any amount once per year. If you extend with fresh contributions, the maximum deposit remains Rs 1.5 lakh per year, and withdrawals are limited to 60% of the balance at the start of the extension block. The calculator shows the maturity at 15 years. To project beyond that, run a new calculation with the balance at year 15 as the starting principal and your chosen extension period.

FAQ

Can I have more than one PPF account?

No. An individual can hold only one PPF account in their name. If a second account is opened by mistake, it must be closed and the deposits transferred to the original account. Minor accounts opened by a parent or guardian are separate and allowed, but the total deposit across the parent's own account and the minor's account cannot exceed Rs 1.5 lakh per year for the parent.

What happens to the PPF account if I move abroad?

A PPF account can only be held by a resident Indian. If you become a non‑resident Indian, you must close the account within six months of the change in residency status. The account cannot be extended after maturity if you are an NRI. NRIs are not eligible to open new PPF accounts.

Does the calculator account for the quarterly rate changes?

The calculator uses a single interest rate you enter. The PPF rate can change every quarter. For a long‑term projection, using the current rate gives a reasonable estimate. If rates change significantly, you can re‑run the calculation with the new rate. The calculator is for illustration only and does not guarantee the exact maturity amount.