PPF Calculator — Estimate Your Public Provident Fund Maturity

How PPF interest is calculated

PPF interest is compounded once a year on your balance. If your yearly deposit goes in at the start of the financial year, the maturity value follows this annuity-due formula (regular payments made at the start of each period):

FV = P × [((1 + r)ⁿ − 1) / r] × (1 + r)

Here P is your yearly deposit. r is the annual interest rate (as a decimal). n is the tenure in years. In practice, PPF interest is credited once a year, but it is worked out each month on the lowest balance between the 5th and the last day of the month. That is exactly why depositing before 5 April matters every year.

Worked example

Deposit the maximum ₹1.5 lakh every year for 15 years at 7.1% per year:

FV = 1,50,000 × [((1.071)¹⁵ − 1) / 0.071] × 1.071 ≈ ₹40.7 lakh

You put in ₹22.5 lakh, so the tax-free interest earned is about ₹18.2 lakh. Keep the same deposit going for 20 years and the corpus grows to roughly ₹66 lakh — those last five years add enormous value through compounding.

Key PPF rules to know

• EEE tax status. PPF is exempt-exempt-exempt: deposits up to ₹1.5 lakh a year get the 80C deduction (old regime), the interest is tax-free, and the maturity payout is tax-free. No other fixed-income product in India offers all three.
• 15-year lock-in, with some relaxations. You can take one partial withdrawal a year from the 7th financial year, borrow against it between the 3rd and 6th years, and close it early after 5 years for medical treatment or higher education (with a 1% cut in the interest rate).
• Minimum yearly deposit. Put in at least ₹500 every financial year, or the account becomes “discontinued”. Reviving it costs ₹50 per missed year, and you lose the loan and withdrawal options until you do.
• The rate can change. The government revises the 7.1% rate every quarter, and it can fall — it was above 8% a decade ago. Try a lower rate (say 6.5%) to stress-test your plan.
• One account per person. You cannot hold two PPF accounts. If a second one is found, its balance is merged and the excess interest is taken back.

How to use this PPF calculator

1. Enter your yearly deposit — the amount you put into PPF in one financial year, from ₹500 up to the ₹1,50,000 maximum.
2. Check the interest rate — 7.1% is the current rate. Change it if you want to test what a lower or higher rate would give you.
3. Set the tenure in years — 15 years is the standard PPF term, and you can extend it in 5-year blocks.
4. Press Calculate to see the maturity value, the total you deposited and the interest earned, along with the year-wise growth chart.

That is the formula from the section above in one line: P is your yearly deposit, r is the annual interest rate as a decimal and n is the tenure in years. The extra (1 + r) at the end is there because the deposit goes in at the start of each year, so every deposit earns a full year of interest in its first year too.

What ₹1,50,000 a year becomes at 7.1%

Here is the growth of the maximum yearly deposit at the current rate, worked out exactly as this calculator does:

Compounding does its heaviest work late. Extending the same deposit from 15 to 20 years takes the corpus from ₹40,68,209 to ₹66,58,288 — and by year 20, the interest earned (₹36,58,288) is more than the total you deposited (₹30,00,000). That is why the 5-year extensions after maturity are so valuable if you do not need the money right away.