Public Provident Fund (PPF) Calculator: Master Guide to Tax-Free Wealth
The Public Provident Fund (PPF) is India's premier government-backed, long-term savings instrument designed to offer guaranteed, risk-free returns combined with unmatched triple-tax exemption (EEE status). Whether planning for your retirement, a child's higher education, or building a generational wealth safety net, our free PPF calculator computes your exact yearly interest, cumulative deposits, and final maturity corpus over 15 to 30 years.
How PPF Interest is Calculated: The Mathematical Formula
PPF interest is compounded annually and calculated on the minimum balance in your account between the close of the 5th day and the end of each calendar month. The mathematical formula for annual compounding is:
- F: Total Maturity Amount / Final Corpus.
- P: Annual Investment Amount (Deposited on or before the 5th of April each financial year for maximum compounding).
- i: Annual Interest Rate expressed as a decimal (e.g., 7.1% per annum = 0.071).
- n: Number of Investment Years (Initial mandatory lock-in of 15 years, extendable in 5-year blocks).
PPF Wealth Growth Table: Investing ₹1.5 Lakhs Annually
Investing the statutory maximum limit of ₹1,50,000 per financial year (₹12,500/month) at the benchmark rate of 7.1% creates substantial guaranteed tax-free wealth:
| Investment Horizon | Total Principal Invested | Total Interest Earned | Final Maturity Corpus | Tax Savings (30% Slab) |
|---|---|---|---|---|
| 15 Years (Standard) | ₹22,50,000 | ₹18,18,209 | ₹40,68,209 | ₹6,75,000 |
| 20 Years (1 Extension) | ₹30,00,000 | ₹36,58,070 | ₹66,58,070 | ₹9,00,000 |
| 25 Years (2 Extensions) | ₹37,50,000 | ₹65,58,015 | ₹1,03,08,015 | ₹11,25,000 |
| 30 Years (3 Extensions) | ₹45,00,000 | ₹1,09,44,896 | ₹1,54,44,896 | ₹13,50,000 |
The "5th of the Month" Golden Rule to Maximize Returns
Because interest is calculated on the lowest balance between the 5th and the last day of each month, you must deposit your monthly contribution on or before the 5th. If you deposit on the 6th, you forfeit that entire month's interest on the new deposit. For lump-sum investors, depositing the full ₹1.5 Lakhs between April 1st and April 5th maximizes interest for the full financial year, earning thousands of extra rupees over the 15-year tenure.
PPF vs FD vs Mutual Fund SIP vs NPS Comparison
| Feature | PPF | Bank Fixed Deposit (FD) | Equity Mutual Fund (SIP) | National Pension System (NPS) |
|---|---|---|---|---|
| Risk Profile | Zero Risk (Sovereign) | Low Risk (DICGC up to ₹5L) | Moderate to High | Market-Linked |
| Average Returns | 7.1% (Quarterly Review) | 6.5% – 7.5% | 12.0% – 15.0% (Historical) | 9.5% – 12.0% |
| Tax Status | EEE (100% Tax-Free) | Taxable as per slab | LTCG 12.5% above ₹1.25L | 60% Tax-Free / 40% Annuity |
| Lock-in Period | 15 Years | 7 days to 10 years | Nil (ELSS: 3 Years) | Till Age 60 |
Understanding PPF Extension Rules (With vs Without Contributions)
- Extension with Fresh Deposits: You can extend in 5-year blocks by submitting Form H within one year of maturity. You continue to earn interest and claim 80C deductions. During each 5-year extension, you can withdraw up to 60% of the balance present at the start of that extension block.
- Extension without Fresh Deposits: If no form is submitted, the account automatically extends. The entire corpus continues earning the prevailing interest rate indefinitely, and you can make one withdrawal per financial year of any amount.
Partial Withdrawal & Loan Facilities Against PPF
PPF accounts offer emergency liquidity without terminating your account:
- Loan Against PPF: Available from the 3rd financial year up to the 6th financial year. The loan amount is capped at 25% of the balance at the end of the second preceding year, at a concessional interest rate of 1% above the prevailing PPF rate.
- Partial Withdrawals: Allowed from the 7th financial year onwards, capped at 50% of the balance at the end of the 4th preceding year or previous year, whichever is lower. Withdrawals are completely tax-free.