Free · Add a long list carefully

Precise Number List Sum

Add many values with a method that reduces floating-point rounding loss.

  • Real sum calculation
  • Private in your browser
  • Text, CSV, and JSON

Try the calculation

This tool uses simple-statistics 7.10.0. Start with the example or enter your own numbers.

Your numbersCommas, spaces, and new lines all work
The library runs in this tab. Your numbers are not uploaded or saved.
Result
Ready for your numbersChoose “Add the numbers” to see the answer.

Powered by simple-statistics 7.10.0, an open-source JavaScript library available under the ISC license.

Three simple steps

How to use it

  1. Use the example or enter your own numbers.
  2. Set any option that appears below the number list.
  3. Press “Add the numbers,” then read or download the result.

Your numbers stay on this device

simple-statistics runs inside this browser tab. Bookify does not upload or save your list. The tool explains the calculation, but a number cannot judge data quality, study design, or what caused a pattern.