Algebra & Equations
Arithmetic Series Sum
Sum of the first n arithmetic terms.
Formula
Formula
Sn = n2 · (2a1 + (n−1)d)
Variables
| Symbol | Definition | Type & range | Units | Role |
|---|---|---|---|---|
| a₁ | first term | computed result | — | result |
| d | common difference | real number (ℝ) | — | input |
| n | number of terms | integer (ℤ) | — | input |
Try it yourself
Interactive calculator
Worked examples
Example 1
Givenfirst term a₁ = 1, common diff d = 1, n = 100
Result5050
Example 2
Givenfirst term a₁ = 2, common diff d = 3, n = 10
Result155