Math

Geometric Sequence Calculator

nth term and sum of the first n terms of a geometric sequence.

Free to use — no sign-up or login.

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This free Geometric Sequence Calculator covers nth term and sum of the first n terms of a geometric sequence.

a_n = a1 r^{n−1}; finite sum uses (1−r^n)/(1−r) when r ≠ 1. Related math tools sit beside How it works, with no account required.

Using the Geometric Sequence Calculator

nth term and sum of the first n terms of a geometric sequence. Typical inputs are First term a₁, Ratio r and n. How it works beside the form states the identity the Geometric Sequence Calculator applies.

FAQ

How do I use the Geometric Sequence Calculator?

Open the Geometric Sequence Calculator, fill First term a₁, Ratio r and n, and read the result. a_n = a1 r^{n−1}; finite sum uses (1−r^n)/(1−r) when r ≠ 1.

What formula does the Geometric Sequence Calculator use?

The Geometric Sequence Calculator uses the identity in How it works. In words: a_n = a1 r^{n−1}; finite sum uses (1−r^n)/(1−r) when r ≠ 1.