PPF Calculator

How does this tool get from a yearly deposit to a maturity amount?

This tool uses annual compounding with the deposit placed at the start of each year. For every year it adds the deposit to the running balance and multiplies the result by one plus the rate, so a ₹1,00,000 deposit earns a full year of interest in the year it goes in. The maturity amount is the balance after the last year. Total deposited is the yearly deposit times the number of years, and total interest is the difference.

Which interest rate does it use, and what year does that rate belong to?

The rate field starts at 7.1% a year, and the code attaches no financial year or quarter label to it, so treat it as a starting value you can overwrite. Clearing the box counts as a rate of 0%, which this tool treats as a 0% rate, and a negative rate is also treated as 0%. Government savings-scheme rates are notified periodically and Indian tax rules change in nearly every Union Budget, while the tool’s defaults are not updated automatically, so the scheme notification, the Income Tax Department or a qualified chartered accountant governs.

What happens at 0% interest?

A rate of 0 is accepted and gives a maturity amount equal to the total deposited, a total interest of ₹0 and a multiplier of 1.00×. Clearing the rate box gives exactly this result, because an emptied number box becomes 0 and is not replaced by 7.1%.

How long can the duration be?

The tool treats 15 years as the floor, so any shorter entry is raised to 15. A longer entry is rounded up to 15 plus whole blocks of five years: 16 to 20 becomes 20, 21 to 25 becomes 25. It assumes the full deposit is made in every one of those years, including the extension years, and it does not model an extension without fresh deposits.

What is the deposit limit in the tool?

A yearly deposit above ₹1,50,000 returns an error message instead of a result. A deposit of zero or less returns a maturity amount of ₹0. The tool does not enforce a minimum deposit and does not ask whether the money goes in as a lump sum or in instalments, because both are treated as one amount at the start of the year.

What does the tool leave out?

It does not model month-by-month interest on the lowest balance, a change of rate part-way through the term, partial withdrawals, loans against the account, premature closure or any tax treatment. It uses one constant rate for the whole term, so the answer is an illustration of the arithmetic rather than a forecast of what an account will hold.

What do the wealth multiplier and the duration line show?

The multiplier is the maturity amount divided by the total deposited, shown to two decimals. The duration line shows the number of years actually used after the 15-year floor and the five-year rounding, which can differ from what you typed. The line for the interest rate repeats the rate used in the calculation.