➗ Arithmetic Series Sum Calculator
Find the sum of the first n arithmetic-sequence terms.
Result
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How this calculator works
Find the sum of the first n arithmetic-sequence terms.
Formula
Sₙ=n/2[2a₁+(n-1)d]
Example
The first 10 terms of 3,7,11,... sum to 210.
Frequently asked questions
What does the Arithmetic Series Sum Calculator do?
Find the sum of the first n arithmetic-sequence terms.
Are the results exact?
The calculator follows the displayed formula. Rounded display values may differ slightly from full-precision results.
Can I use negative or decimal values?
Most fields accept decimals and negative values when they make sense for the formula.
How should I check an important result?
Review the formula, verify your entries, and confirm high-stakes work with a qualified teacher or professional.