Skip to content
math

Sequence Calculator

Find the nth term and sum of an arithmetic or geometric sequence.

nth term
14
Sum of n terms
40

How it works

  1. 1Choose an arithmetic or geometric sequence.
  2. 2Enter the first term, the common difference (d) or ratio (r), and the number of terms (n).
  3. 3Read the nth term and the sum of the first n terms.

Use cases

  • Find the nth term of a sequence for homework.
  • Sum a series of payments or measurements.
  • Explore arithmetic and geometric growth.

Frequently asked questions

What is an arithmetic sequence?

A sequence where each term increases by a fixed amount d. The nth term is a + (n − 1)d.

What is a geometric sequence?

A sequence where each term is multiplied by a fixed ratio r. The nth term is a × r^(n − 1).

How is the sum found?

Arithmetic: n ÷ 2 × (2a + (n − 1)d). Geometric: a × (rⁿ − 1) ÷ (r − 1), or a × n when r = 1.

See all →