How to Calculate the Sum of a List of Numbers

Step-by-step

1. Type or paste your numbers, separated by commas, spaces, semicolons or new lines.
2. Read the sum, the count and the average shown below the box.
3. If the tool reports ignored entries, find the typo in your list. Anything that is not a number is skipped.
4. Enter large numbers without thousands separators, such as 1000 instead of 1,000.
5. Check the total against a rough estimate to catch a missing or doubled value.

Why commas can cause surprises

Because a comma separates numbers here, 1,000 is read as the two numbers 1 and 000. The tool shows a warning when a value looks like it uses a thousands separator. Enter 1000 to avoid it.

Decimals and precision

Results show up to ten decimal places and are rounded to 12 significant digits, so 0.1 + 0.2 shows 0.3 instead of 0.30000000000000004.

Checking a long list

For long lists, compare the count with the number of items you expected. A count that is lower than expected usually means some entries were ignored.