Compound Interest

If the interest at the end of a year or fixed period is added to the sum lent, and the amount so obtained becomes the principal for the next period, then sum of the money is said to be lent at compound interest.

Working Formulae:

If P is the principal, T is the number of years and R is rate of interest per annum.
Then Amount= P[1+R/100]^T

Note 1 : When the interest is compounded half yearly
Amount= P[1 +(R/2)/100]^2T = P[1+R/200]^2T

Note 2: When the interest is compounded quarterly

Amount= P[1 +R/4/100]^4T = P[1+R/400]^4T
Compound interest is obtained when principal is subtracted from Amount.