Geometric sequence calculator
Find the nth term and the sum of the first n terms of a geometric sequence.
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Tool guide
Geometric sequence calculator: how it works
Practical information to understand the result and use this tool correctly.
About Geometric sequence calculator
Geometric sequences multiply by a constant ratio r each step.
The finite geometric series sum has a closed form for r≠1.
Models compound growth, decay, and recursive scaling.
How to use it
- 1Enter a₁, r, and n ≥ 1.
- 2Calculate aₙ and Sₙ.
- 3Avoid extreme |r|ⁿ that overflow.
Frequently asked questions
- r = 1?
- Then aₙ = a₁ and Sₙ = n·a₁.
- Infinite series?
- This tool sums the first n terms only.