Arithmetic Sequence Term Calculator

About this calculator

An arithmetic sequence is a list of numbers where each term is found by adding the same fixed amount — the common difference, d — to the one before it, such as 3, 7, 11, 15 (common difference 4). Rather than counting forward term by term, the nth term can be found directly with the formula a_n = a₁ + (n − 1)d, where a₁ is the first term and n is the position you want.

Algebra courses introduce arithmetic sequences as the simplest kind of pattern-based reasoning before moving on to geometric sequences and series, and the same structure models any real-world quantity that changes by a constant amount each step — seating rows that each add a fixed number of extra seats, a savings plan that adds the same fixed deposit every period, or a simple interest schedule where the same amount of interest accrues each term.

This calculator takes the first term, common difference, and term position and returns the value of that specific term.