Math
Arithmetic Sequence Calculator
Use this arithmetic sequence calculator for patterns that add the same common difference each step.
Try an example
Result
nth term
—
- Sum through n
- —
Student quick launch
Grade planning, algebra checks, and formulas students reach for most.
Study path
Use this calculator with
Follow these when you want the formula behind the answer, a short lesson, or nearby tools in the same topic.
What the arithmetic sequence calculator solves
Use this arithmetic sequence calculator for patterns that add the same common difference each step.
Formula
How to use it
- Enter the first term.
- Enter the common difference.
- Enter which term number you want.
How to read the answer
Arithmetic sequences grow by repeated addition, so the graph of term number versus value is linear.
Common mistakes and edge cases
- The first term is n = 1, not n = 0.
- The common difference can be negative.
- Use geometric sequence formulas for repeated multiplication.
Worked examples
Increasing sequence
nth term
31
Decreasing sequence
nth term
10
Frequently asked questions
What is the common difference?+
It is the amount added to get from one term to the next.
Can the difference be zero?+
Yes. Then every term is the same and the sum is n times that term.
About this calculator
- Written by
- mathcheck editorial team
- Last reviewed
- May 15, 2026
Method
- Uses the values entered by the user and stable formulas documented on the page.
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Last updated: May 15, 2026