How to use this calculator

An arithmetic series adds consecutive terms from an arithmetic sequence.

The method

Sₙ = n/2 × (2a₁ + (n−1)d)

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: 5, Common difference d: 3, Number of terms n: 10

Select Calculate to evaluate these example values.

Scope and limitations

n must be a positive whole number.

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.