AllEasyToolsMathematics
Arithmetic sequence
Arithmetic sequence: calculate from your inputs and inspect the formula. No account required. Processing stays in your browser.
aₙ=a₁+(n−1)d; Sₙ=n(a₁+aₙ)/2
Check units and the formula domain. Numerical results are rounded.
How to use this calculator
- Identify the quantities and convert them to the units shown.
- Apply the formula first, then compare with the substitution and result.
- Check the assumptions and whether the order of magnitude makes sense.
Levels are approximate topic groupings, not a complete curriculum for every country. Numerical results are rounded and may lose precision for extreme or nearly singular inputs.
A practical example
Use these sample inputs to check the calculation before entering your own values.
- First term
- 2
- Difference
- 3
- Number of terms
- 10
Result for this example
- Nth term
- 29
- Sum
- 155