How PPF Interest Is Calculated
Blog by Aliceblue News Desk
02 November 2026
9 minutes
PPF interest is calculated using your account balance every month, but the interest is added to your account only at the end of the financial year. For each month, the balance considered is the lowest balance between the close of the 5th day and the end of that month.
This makes the date of contribution important. If your contribution reaches the PPF account on or before the 5th, it can earn interest for that month. If it reaches the account later, it generally starts earning interest from the following month.
PPF currently earns 7.1% per year for October-December 2026, with interest compounded annually.
Table of Contents
Quick Answer
PPF interest works in three steps:
- The eligible balance is determined separately for every month.
- Interest is calculated on the lowest balance between the close of the 5th day and month-end.
- The accumulated interest is credited at the end of the financial year.
A simplified monthly calculation is:
Monthly Interest = Eligible Monthly Balance × Applicable Annual PPF Rate ÷ 12
If the Government changes the PPF rate during the year, the rate applicable to the relevant period must be used.
What Is the PPF Interest Calculation Rule?
PPF interest is based on the balance held in the account during each month. Official India Post PPF operating guidance states that interest is allowed for a calendar month on the lowest balance at credit between the close of the fifth day and the end of the month. The accumulated interest is then credited to the account at the end of the year.
For example, suppose your account balance is ₹3 lakh on April 5 and you deposit another ₹50,000 on April 12. The additional ₹50,000 does not increase the balance used for April’s interest calculation because it arrived after the monthly cut-off. It can begin contributing to the calculation from May, assuming it remains in the account.
Why Does the 5th-Day Rule Matter?
Suppose you have ₹2 lakh in your PPF account. Now compare two situations.
Deposit on April 4
You add ₹50,000.
The balance considered for April can be:
₹2,50,000
because the additional money was credited before the monthly cut-off.
Deposit on April 10
You add the same ₹50,000.
The balance used for April’s interest would remain:
₹2,00,000
The additional ₹50,000 would normally begin earning interest from May. This is why a difference of only a few days can affect your PPF interest.
PPF Interest Formula
A simple way to estimate interest for one month is:
Monthly PPF Interest = Eligible Balance × Annual PPF Rate ÷ 12
At the current 7.1% annual rate, suppose the eligible balance for a month is ₹5 lakh.
The approximate interest for that month would be:
₹5,00,000 × 7.1% ÷ 12
= ₹2,958 approximately
The account provider performs the actual calculation automatically.
The formula is mainly useful for understanding how balance and contribution timing affect the interest earned.
PPF Interest Calculation Example
Suppose your PPF balance is ₹5 lakh at the beginning of April.
Assume:
- the balance remains unchanged throughout the year,
- there are no withdrawals,
- and the interest rate remains 7.1% throughout the year.
Monthly interest would be approximately:
₹5,00,000 × 7.1% ÷ 12 = ₹2,958
For 12 months:
₹2,958 × 12 ≈ ₹35,500
So the approximate interest for the year would be ₹35,500.
At year-end, this interest is credited to the account, taking the balance to approximately:
₹5,35,500
This example is simplified because PPF rates can change during a financial year.
How Much Difference Does Depositing Before the 5th Make?
Suppose you deposit ₹50,000 on April 4 instead of April 10.
At a 7.1% annual rate, the additional interest for April is approximately:
₹50,000 × 7.1% ÷ 12 ≈ ₹296
So depositing after the cut-off would cost roughly one month’s interest on that ₹50,000.
For a single contribution, the difference may look small. But if contributions are repeatedly made after the 5th every month, the lost interest can add up over time.
Lump Sum vs Monthly PPF Contributions
Suppose you plan to contribute the full ₹1.5 lakh annual limit and assume a constant 7.1% rate.
Option 1: ₹1.5 Lakh Available From April
If ₹1.5 lakh qualifies for interest for all 12 months:
Approximate first-year interest = ₹10,650
Option 2: ₹12,500 Every Month
If ₹12,500 is deposited by the 5th of every month, each instalment earns interest for a different number of months.
The first instalment earns for 12 months, while the December instalment earns for only four months of the financial year.
Under the same 7.1% assumption, interest on those monthly contributions during that financial year would be approximately ₹5,769.
Contribution Method | Amount Invested | Approx. Interest on New Contributions* |
₹1.5 lakh available from April | ₹1,50,000 | ₹10,650 |
₹12,500 by the 5th each month | ₹1,50,000 | ₹5,769 |
*Illustration assumes no opening balance and a constant 7.1% rate throughout the year.
The lump sum earns more because more of the money remains in the account for a longer period. However, monthly contributions may still be more practical for someone investing from salary.
If PPF forms only one part of your long-term plan, Alice Blue’s guide on long-term investing in Indian stocks explains how market-linked investments differ from fixed-income options in terms of risk, liquidity, and growth potential.
How Annual Compounding Works?
PPF interest is compounded annually. Suppose you have ₹5 lakh and earn ₹35,500 in interest during the year.
After the interest is credited:
New balance = ₹5,35,500
In the following year, this higher balance can also earn interest. That is how earlier interest begins earning further interest over time.
The sequence is:
Balance is considered monthly → interest is credited annually → credited interest becomes part of the balance for future years.
Does the PPF Interest Rate Stay Fixed for 15 Years?
No. The PPF rate that applies when you open the account is not locked in for the entire 15-year tenure.
The Government reviews small-savings rates every quarter. The Department of Economic Affairs publishes the official small-savings interest-rate notifications, including the rates applicable to PPF.
For October 1 to December 31, 2026, the PPF rate remains 7.1% per year.
If the rate changes in a later quarter, the new applicable rate is used according to the scheme rules. Depositing money early gives it more time to earn interest. It does not lock today’s interest rate for the remaining PPF tenure.
How to Avoid Losing PPF Interest?
Deposit by the 5th:
If you contribute monthly, try to make sure the money reaches the account by the 5th.
Invest Earlier If the Money Is Already Available:
If you already plan to contribute a lump sum for the year, depositing it earlier allows the money to remain eligible for more monthly interest calculations.
Keep Cash Flow in Mind:
Do not use emergency money simply to make an April PPF contribution. PPF is a long-term account, while emergency money needs to remain easily accessible.
For broader long-term planning, Alice Blue’s guide on investing in mutual funds for retirement explains why retirement savings are usually spread across different types of investments rather than depending on one product alone.
Check the Current Rate:
Do not assume the PPF rate shown in an old calculator or article still applies. The Government reviews the rate quarterly.
Common Mistakes
- Thinking PPF interest is added every month: The calculation uses monthly balances, but interest is credited annually.
- Ignoring the 5th-day rule: Contributions credited after the cut-off may miss that month’s interest.
- Using only the month-end balance: The scheme uses the lowest balance between the close of the 5th day and month-end.
- Assuming 7.1% is fixed for 15 years: The PPF rate is reviewed quarterly.
- Using one interest rate for a year when rates changed during that year: Use the rate applicable to each relevant period.
- Assuming an early April deposit locks the interest rate: It only gives the contribution more months to earn interest.
- Comparing lump sum and monthly deposits without considering timing: Earlier money earns for more months.
- Using emergency savings for PPF: Extra interest is not worth losing short-term liquidity.
Tips for Beginners
- Remember the 5th-day cut-off for contributions.
- Check that the contribution is credited to the PPF account in time.
- Use the latest PPF interest rate in calculations.
- Treat long-term calculator results as estimates because future rates can change.
- If investing monthly, consider automating the contribution before the 5th.
- If investing a lump sum, contributing earlier may earn more interest if your cash flow permits.
- Keep emergency savings separate.
- Check the annual PPF statement to confirm deposits and interest credits.
Conclusion
PPF interest calculation is mainly about balance, timing, and the applicable interest rate. For every month, interest is calculated using the lowest account balance between the close of the 5th day and the end of that month. These monthly calculations are combined, and the interest is credited at the end of the financial year.
Depositing by the 5th allows a new contribution to participate in that month’s calculation. Depositing later generally means waiting until the next month.
PPF currently pays 7.1% per year, but the rate is reviewed quarterly. So use current rates for calculations and treat long-term projections as estimates rather than guaranteed maturity values.
Frequently Asked Questions
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