Arithmetic Sequence Calculator


This Arithmetic Sequence Calculator calculates the n-th term and the sum of the first n terms of an arithmetic sequence, given the first term of the sequence and the common difference.


Precision: decimal places

First Term (a1):
Difference (d):
Number of Terms (n):

Last Term Value:
Sum of All Terms:


Arithmetic sequence formula

In mathematics, an arithmetic sequence, or arithmetic progression is a sequence of numbers such that the difference between the consecutive terms is constant and is called the common difference. So, the formula for the \(n\)-th term is:

$${ a }_{ n } ={ a }_{ 1 } + d ⋅ (n – 1),$$

where \(d\) is the common difference.

The sum of the numbers in an arithmetic progression, also known as an arithmetic series, is expressed by the following formula:

$$n ⋅\frac { { a }_{ 1 } + { a }_{ n }}{ 2 }.$$


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Check out our other math calculators such as Geometric Sequence Calculator or Factorial Calculator.