Summation Calculator

The Summation (Sigma) Calculator evaluates a series written in sigma notation, computing the total of a mathematical expression as an index runs from a lower bound to an upper bound. It saves you from adding up every term by hand, which becomes tedious or error-prone once the range grows large.

Enter the expression using the index variable, then set the lower and upper bounds and read off the total instantly. It is handy for homework, statistics formulas, finance series like loan or annuity sums, and quickly checking a derivation.

Tip: the expression supports common operators and functions, so you can build everything from simple arithmetic sums to more involved terms. Everything runs locally in your browser, so your input never leaves your device.