Your files stay on your device

# Arithmetic sequence calculator

Solve arithmetic and geometric sequences from a first term and difference, two known terms, or a pasted list, with formulas, sums, and steps shown.

Enter a first term, two terms, or a list to solve the sequence.

Two known terms pin the whole sequence down: subtracting and dividing gives the step, and the step walked back gives the first term. A pasted list is only trusted when it is truly evenly spaced (or truly one constant ratio); anything else is rejected with the first conflicting pair named. The sum uses the closed formula, not a loop of additions, so 1 through 100 lands on 5050 exactly.
Options

## More unit & math tools

- [Average and median](/converters/statistics)
- [Fraction calculator](/converters/fractions)
[All unit & math tools](/converters)

Was this tool useful?
YesNo

---

Canonical HTML: https://nutter.tools/converters/arithmetic-sequence-calculator
Markdown version: https://nutter.tools/converters/arithmetic-sequence-calculator.md
Plain-text version: https://nutter.tools/converters/arithmetic-sequence-calculator.txt
Agent index: https://nutter.tools/llms.txt