Enter the first term, the common difference, and the number of terms to get the sum of an arithmetic series and the value of its last term. An arithmetic sequence adds the same amount at each step, like two, five, eight, eleven, and its sum has a neat closed form that saves you from adding every term by hand. This calculator uses the classic formula, the number of terms times the average of the first and last term, so even a sequence of thousands of terms is instant. It also reports the nth term so you can check the pattern. This is handy for the well known sum of consecutive whole numbers and for any evenly spaced list. Everything is computed locally in your browser, so the answer appears at once and nothing you enter is sent anywhere.
It is the sum of a sequence where each term increases by a fixed common difference, such as 2, 5, 8, 11.
The tool uses the formula n times the first term plus the last term, divided by 2, which pairs terms from each end.
Yes. From the first term and common difference it returns the value of any term in the sequence.
Enter the first term, the common difference, and the number of terms to get the sum of an arithmetic series and the value of its last term. An arithmetic sequence adds the same amount at each step, like two, five, eight, eleven, and its sum has a neat closed form that saves you from adding every term by hand.
Yes. Arithmetic Series Sum Calculator is completely free, with no sign-up and no usage limits.
Yes. Arithmetic Series Sum Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Arithmetic Series Sum Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.