If an approximation will do, try the continuous version - then you can throw some integration at it.
Above is an example of future value of an amount at an incresing rate:Code:YR RATE INTEREST BALANCE 0 1000.00 1 .03 30.00 1030.00 2 .033 33.99 1063.99 3 .0363 38.62 1102.61 4 .03993 44.03 1146.64
$1000.00 at rate 3% 1st year, then the rate increasing by .10 each year.
As example, year2 rate = .03 * 1.10 = .033
What is the formula to calculate the future value in such circumstances?
Thanks. But to be exact, only a "looper" will do it, I guess:
FOR y = 1 TO n
k = a * r [this period's interest]
a = a + k [this period's resulting principle]
r = r * i [update rate]