Your fixed deposit grows based on two factors: the interest rate offered and how often that interest is added to your principal (interest payout frequency). This repeated addition of interest, called compounding, can significantly boost your earnings over time.
The formula for fd interest calculator is :
A=P(1+r/n)^n*t,
where A is the maturity amount
P is the principal
r is the rate of interest
t is the number of years
n is compounded interest frequency