High-Precision Summation (Sum) Calculator

New Support Thousand Separators now.

Add numbers separated by a comma (plus a space) [example1],a space [example2] or a line break [example3]:
If your text contains other extraneous content, you can use our Number Extractor to extract numbers before calculation.

About High-Precision Summation (Sum) Calculator

Welcome to our high-precision summation calculator, your reliable tool for finding the sum of a list or series of numbers quickly and accurately. Whether you are looking to add a list of numbers, find the sum of positive or negative numbers, or add numbers together without the hassle of manual calculations, this is your go-to number adder tool.


  • High Precision: Calculate the sum with up to 1000 decimal precision.
  • User-Friendly: No need to use the plus (+) sign between the numbers.
  • Supports Thousand Separators: Facilitating the addition of large numbers with ease.
  • Mobile Version Available: Install it as a PWA on your home screen and add up numbers on the go.


To add numbers together, separate each one using a comma followed by a space, a space alone, or a line break, and the tool will automatically calculate the sum, presenting you with the total sum.

The adding calculator has been tested rigorously, proving its capability to instantly add a list of numbers reaching up to 10k in quantity, showcasing its efficiency and reliability.

Absolutely. The tool maintains full functionality when you add numbers that are negative; just ensure to retain the negative sign with the numbers.
Yes, it supports the use of thousand separators, facilitating the addition of large numbers with ease.

Yes, while primarily designed as a summation calculator, it can also function as a series sum calculator, helping you find the sum of a series of numbers with ease. If you are looking to calculate the sum of a specific series, you might find our Geometric Sequence Calculator or Arithmetic Sequence Calculator more suitable.

Yes, the sum tool is developed as a PWA (Progressive Web App), allowing you to install it on your home screen, provided your device and browser support PWA, offering a convenient way to add a list of numbers on the go.


Summation from Wikipedia

Addition from Wikipedia

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