Online calculator to calculate the sum of the terms in a geometric sequence.

If A1, A2, ... , An, ... is a geometric sequence with common ratio r, this calculator calculates the sum Sn given by

Sn = A1 + A2 + ... + An = a1(1-r^{n})/(1-r)

and the nth term an = a1 r^{n - 1}

How to use the calculator

1 - Enter the first term A1 in the sequence, the common ratio r and n n the number of terms in the sum then press enter. A1 and r may be entered as an integer, a decimal or a fraction. n must be a positive integer.