You put money into your Public Provident Fund every year, but how much will actually be waiting for you after 15 years? The answer takes three numbers and one simple rule, and a single date in the calendar can change the result by more than ₹2.5 lakh.
What the PPF is, in plain terms
The Public Provident Fund is a government-backed savings scheme in India, first introduced in 1968 and updated by the PPF Scheme of 2019. Any Indian resident can open an account at a nationalised bank, an authorised private bank or a post office.
The rules that matter for the math are short:
- You must deposit at least ₹500 and at most ₹150,000 per financial year. Anything above ₹150,000 earns no interest at all.
- The interest rate is announced every quarter by the Ministry of Finance. It was 7.1% a year for the first quarter of FY 2024-25.
- Interest is compounded once a year and credited in March.
- The account runs for 15 years, after which you can withdraw everything or extend in blocks of 5 years.
On top of that, the PPF sits in the EEE (exempt, exempt, exempt) tax basket: deposits qualify for a deduction under Section 80C in the old tax regime (capped at ₹150,000 a year), and both the interest and the maturity amount are tax-free.
The formula, step by step
Because interest compounds once a year, you can work it out one year at a time:
Balance at the end of the year = (balance at the start of the year + this year’s deposit) × (1 + interest rate)
In words: add what you deposited to what was already there, then grow the total by the year’s rate. Repeat 15 times. If you deposit the same amount every year and the rate stays the same, the 15 steps collapse into a single shortcut: deposit × [((1 + rate)15 − 1) ÷ rate] × (1 + rate). It looks heavy, but it simply adds up 15 deposits, each one grown for the number of years it stayed in the account.
A real example with ₹1.5 lakh a year
Say you deposit the full ₹150,000 at the start of every financial year, and, to keep the example readable, assume the rate stays at 7.1% for all 15 years (in reality it is revised every quarter).
- Year 1: ₹150,000 × 1.071 = ₹160,650
- Year 2: (₹160,650 + ₹150,000) × 1.071 = ₹332,706 (rounded)
- After 5 years: about ₹9.26 lakh
- After 10 years: about ₹22.30 lakh
- After 15 years: about ₹40.68 lakh
You deposited ₹22.5 lakh in total, so roughly ₹18.2 lakh of the final amount is interest, and none of it is taxed. A smaller saver putting in ₹5,000 a month (₹60,000 a year) at the start of each year would end up with about ₹16.27 lakh after 15 years, from ₹9 lakh deposited.
The 5th-of-the-month rule that costs people lakhs
Here is the detail most savers miss: PPF interest for each month is calculated on the lowest balance between the close of the 5th day and the last day of that month. Money that lands on the 6th earns nothing for that month.
That is why the example above assumes a deposit at the very start of the financial year, before 5 April. If the same ₹150,000 went in at the very end of each financial year instead (in March, so it earns almost nothing that year), the 15-year total drops to about ₹37.99 lakh. Same money, same rate, about ₹2.7 lakh less, purely because of timing.
Common mistakes and nuances
- Treating 7.1% as fixed. The rate changes quarterly. At 6.1% instead of 7.1%, the same ₹150,000 a year grows to about ₹37.33 lakh, not ₹40.68 lakh. Rerun the math with the current rate.
- Depositing more than ₹150,000. The extra earns zero interest, so it only parks your money.
- Skipping a year. An account with no deposit in a year becomes inactive. Reviving it costs a ₹50 penalty plus the ₹500 minimum for each missed year.
- Forgetting the extension option. At maturity, if you do nothing within a year, the account is extended by 5 years without new contributions and keeps earning interest. Leaving ₹40.68 lakh untouched for 5 more years at 7.1% would take it to about ₹57.33 lakh.
p>Finance writer R.K. Mohapatra, author of “Retirement Planning: A Simple Guide for Individuals”, has argued that in a falling interest rate era the PPF makes particular sense for people in higher tax brackets, precisely because of that triple tax exemption. Whatever your bracket, the method stays the same: deposit early in the year, run the year-by-year formula with the current rate, and you will know your maturity amount before the bank tells you.
