# Geometric series (sum of the numbers)

## Description

A geometric progression, also known as a geometric sequence, is a sequence of numbers where each term after the first is found by multiplying the previous one by a fixed, non-zero number called the common ratio. The sum of the numbers in a geometric progression can be calculated by the initial value and common ratio of the progression.

Related formulas## Variables

S | Nth term of the series (dimensionless) |

a | First term (dimensionless) |

r | Common ratio (dimensionless) |

n | Number of terms (dimensionless) |