How to use this calculator

A geometric sequence changes by multiplying each term by the same ratio.

The method

aₙ = a₁ × r^(n−1)

Enter your values in the labeled fields and choose Calculate. The result panel shows the answer and supporting values when useful.

WORKED EXAMPLE INPUT

First term a₁: 3, Common ratio r: 2, Term number n: 8

Select Calculate to evaluate these example values.

Scope and limitations

Very large n or |r| can exceed the finite numeric range.

Common questions

Can I use different units?

Use consistent units unless this page is a unit converter. The result follows the units implied by the inputs.

Are results exact?

Displayed values may be rounded. Keep extra precision for important follow-up calculations.

Methods & verification

Formulas use standard mathematical definitions and fixed unit factors where applicable. See our methodology for numerical conventions, rounding, privacy, and limitations.