The Series Sum Calculator is a free online tool that helps you quickly find the sum of arithmetic, geometric, or custom series. By entering the first term, common difference or ratio, and the number of terms, this calculator instantly gives you the total of the sequence. Whether you are a student solving math problems, a teacher preparing examples, or anyone who needs fast results, this calculator makes it simple and accurate. It works for arithmetic progression (AP), geometric progression (GP), and even custom lists of numbers, saving you time and effort in manual calculations