Cumulative Sum Calculator
Enter signed decimal values to calculate an exact cumulative sum locally, without binary floating-point rounding.
A QUICK WALKTHROUGH
How to use this tool
- Enter decimal values separated by commas, spaces, semicolons, or line breaks.
- Calculate to review every running total and the final total.
- Copy the running totals when you need an auditable sequence of results.
Exact decimal addition
Values are parsed as signed decimal strings and added with integer arithmetic after aligning their decimal places. The result does not use binary floating-point addition.
Input boundaries and precision
A calculation accepts up to 10,000 values. Each value may contain up to 100 integer digits and 30 digits after the decimal point. Exponential notation, grouping separators, and other non-decimal syntax are rejected.
Every step is visible
The tool displays one numbered running total for each input value, plus the final total. Trailing fractional zeroes are removed from the display while the exact value is preserved.
GOOD TO KNOW
Common questions
Is the sum exact?
Yes. Supported decimal strings are aligned and added as integers, avoiding binary floating-point rounding.
Which values are accepted?
Signed decimal values with a decimal point are accepted, including whole numbers such as 12 and values such as .5. Exponential notation is not accepted.
How many values can I enter?
Up to 10,000 values per calculation, with the stated 100 integer digit and 30 fractional digit limits for each value.
Where is the data processed?
Parsing and addition run locally in your browser; values are not uploaded or stored by this page.