Series Sum
Free Series Sum calculator with clear step-by-step results.
About Series Sum
Sums an arithmetic series efficiently.
Formula
Formula
Sum = n/2 × (first + last)
Worked example
With the default values below, Series Sum returns Sum of 100.00. Change any input above and every figure here is recalculated in your browser.
Inputs used
- First termminimum 0
- 1
- Common differenceminimum 0
- 2
- Number of termsminimum 1
- 10
Results
- Sum
- 100.00
- Last Term
- 19.00
- Average Term
- 10.00
Step by step
- 1Values used
- 2Formula
- 3Sum= 100.00
- 4Last Term= 19.00
- 5Average Term= 10.00
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How does this calculator work?
Sums an arithmetic series efficiently.
Why does this matter?
Only valid for arithmetic sequences.