Number Sum Calculator
Paste or type your numbers — separated by commas, spaces, or line breaks — and get the sum instantly, with the count and average included. Works with integers, decimals, and negative values.
Sum
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How it works
Sum = n₁ + n₂ + … + nₖ — every number in your list added together.
Worked example
The list 4.50, 3, 2.50 has three numbers: 4.50 + 3 + 2.50 = 10, with an average of 3.333333.
Frequently asked questions
How do I add up a list of numbers?
Paste or type your numbers into the input box, separating them with commas, spaces, semicolons, or line breaks. The total updates instantly as you type — for example, 12 + 7.5 + 40 gives 59.5. The calculator also shows how many numbers it found and their average, and you can copy the result to your clipboard with one click.
What separators can I use between numbers?
Commas, spaces, semicolons, tabs, and line breaks all work as separators, in any combination. A comma between digits with no space is read as a decimal separator, so 3,5 becomes 3.5, while 3, 5 stays two numbers. Thousands separators are recognized too: 1,234 is treated as one thousand two hundred thirty-four, not two values.
Can this tool sum numbers found inside text?
Yes. Switch the input format to Extract from text and paste any content — a receipt, a report, or a sentence like "20 apples and 30 pears". The calculator finds every numeric value, ignores the surrounding words and currency symbols, and adds them up. In this example the result is 50, calculated entirely in your browser.
Does the calculator support negative and decimal numbers?
Yes. Integers, decimals, and negative values can be mixed freely in the same list. Entering -5.5, 10, 2.5 produces a sum of 7, and the average is recalculated accordingly. Values like 1,234.50 with both thousands and decimal separators are parsed correctly, so pasted financial data usually works without any cleanup.
How many numbers can it add at once?
There is no fixed limit — the tool comfortably handles thousands of values pasted from spreadsheets or exports. Everything runs locally in your browser with JavaScript, so nothing you enter is uploaded to a server. For very long lists, the calculation details view shows the first twenty addends so the page stays fast and readable.
Why does 0.1 + 0.2 sometimes equal 0.30000000000000004?
Computers store decimals in binary, and 0.1 and 0.2 have no exact binary form, so tiny rounding errors appear at the sixteenth digit. This calculator rounds away that noise, so you see a clean 0.3. If you need exact arithmetic for money, work in cents — enter 150 instead of 1.50 — and convert back at the end.