What is a Flexi Fixed Deposit Calculator?
A flexi fixed deposit (FD) combines the flexibility of a savings account with the higher returns of a term deposit. This calculator estimates the maturity amount and total interest earned on your deposit assuming interest is compounded quarterly — the standard method most banks use for fixed deposits.
How to use it
Enter three values: the deposit amount (principal), the annual interest rate as a percentage, and the term in years (you can use fractions like 1.25 or 2.5). The calculator instantly returns the value of your deposit at maturity and how much of that is interest.
The formula explained
The maturity value uses the compound interest formula with quarterly compounding:
$$A = P \times \left(1 + \frac{r}{4}\right)^{4t}$$
Here P is the principal, r is the annual interest rate written as a decimal (6% = 0.06), and t is the time in years. Because interest is added four times a year, the rate is divided by 4 and the exponent is multiplied by 4. The interest earned is simply \(I = A - P\).
Worked example
Deposit ₹50,000 at 6% annual interest for 2 years. With quarterly compounding, \(r/4 = 0.015\) and \(4t = 8\) periods. $$A = 50000 \times (1.015)^{8} = 50000 \times 1.126493 = ₹56{,}324.63$$ The interest earned is ₹6,324.63.
FAQ
Why quarterly compounding? Most banks credit FD interest every quarter, so compounding four times a year reflects real-world returns more accurately than annual compounding.
Can I enter a partial year? Yes. Use decimals such as 0.5 for six months or 1.75 for 21 months.
Is the result before or after tax? The figures shown are gross. Interest income may be taxable depending on your jurisdiction, so net returns can be lower.
